Mathematics MCQs

A. 1.8 km/hr
B. 3 km/hr
C. 3.6 km/hr
D. 4 km/hr

Let x be the speed of the river.
Ds = (6 + x) km/hr; Us = (6 – x) km/hr
If t hours is the time to row downstream then 4t hours is the time to row upstream.
(6 + x)*t = (6 – x)*4t
6 + x = 24 – 4x
x = 3.6 km/hr

Correct Answer: C. 3.6 km/hr ✔

A. 0.60 minutes
B. 0.36 minutes
C. 0.78 minutes
D. 0.42 minutes

Total distance = addition of length of the two trains = 140 + 120 = 260 metres
As the two trains are travelling in the same direction, their relative speed is:
v = | v1 – v2 | = | 40 – 60 | = 20 km/hr = 20*1000/60 = 1000/3 metres/min
t = 260/ 1000*3
t = 0.78 minutes

Correct Answer: C. 0.78 minutes ✔

A. 2:5
B. 4:3
C. 1:2
D. 1:1

Rayan’s speed = 1000/300 = 3.33 m/s
Hence Ratio  =  1:1

Correct Answer: D. 1:1 ✔

A. 6:8
B. 3:7
C. 5:4
D. 4:3

If the ratio of the speeds of two objects is a:b, then the time taken by them to cover the same distance is
b:a Hence, the answer is 4:3

Correct Answer: D. 4:3 ✔

A. 400
B. 320
C. 240
D. 300

With a full tank, it can travel
360*4/3 = 480 km With 2/3 full tank, it can travel
480*2/3 = 320 km

Correct Answer: B. 320 ✔

A. 20 km
B. 40 km
C. 30 km
D. 10 km

x = 7 km/hr ; y = 3 km/hr
Ds = 10 km/hr ; Us = 4 km/hr
Distance (d) is same. Therefore, if time taken for downstream is t hours, the time for upstream is (t + 6) hours.
10*t = 4*(t + 6)
6t = 24 ; t = 4 hours
d = 10*4 = 40 km

Correct Answer: B. 40 km ✔

A. 36
B. 24
C. 30
D. 18

Let t be his usual time to reach his office and v be his usual speed.
v = d/t ……….(d is the distance Afnan travels while going to his office)
vt = d
At v1 = 4v/5 ; t1 = t + 6
4v/5 = d/(t + 6)
4v/5* (t + 6) = d
4v/5* (t + 6) = vt
On solving we get,
t = 24 minutes

Correct Answer: B. 24 ✔

A. 17 hr
B. 14 hr
C. 12 hr
D. 19 hr

Relative speed = 5.5 – 5 = .5 kmph (because they walk in the same direction)
distance = 8.5 km

time = distance/speed=8.5/.5=17 hr

Correct Answer: A. 17 hr ✔

A. 30 kmph
B. 27 kmph
C. 25 kmph
D. 20 kmph

Distance = 24*50/60 = 20 km New Speed = 20/(40/60)) = 30 kmph

Correct Answer: A. 30 kmph ✔

A. 9
B. 10
C. 12
D. 20

Due to stoppages, the bus travels only 45 kms in an hour (9 kms less). To cover a distance of 9 km at a speed of 54 kmph, time taken
= 9/54 = 1/6 hrs = 10 mins.

Correct Answer: B. 10 ✔

A. (7 , 3) km/hr
B. (6 , 4) km/hr
C. (10 , 4) km/hr
D. None of these

If x: speed of boats man in still water
y: speed of the river
Downstream speed (Ds) = x + y
Upstream speed (Us) = x – y
x = (Ds + Us) / 2
y = (Ds – Us) / 2
In the above problem Ds = 10 ; Us = 4
x = (10 + 4) / 2 = 14/2 = 7 km/hr
y = (10 – 4)/2 = 6/2 = 3 km/hr

Correct Answer: A. (7 , 3) km/hr ✔

A. 2.5 km
B. 7.2 km
C. 7 km
D. 3.6 km

Average speed of Taimoor = (2*2*3)/(2 + 3) = 2.4 km/hr
If d is he distance between the school and Taimoor’s home, then total distance walked by Taimoor = 2d, and the total time taken is 3 hours
2.4 = 2d/3
7.2 = 2d
d = 3.6 km

Correct Answer: D. 3.6 km ✔

A. 80 kmph
B. 102 kmph
C. 120 kmph
D. 140 kmph

Correct Answer: C. 120 kmph ✔

A. 5
B. 6
C. 7
D. 8

Relative speed = Speed of A + Speed of B (∴ they walk in opposite directions)
= 2 + 3 = 5 rounds per hour
=> They cross each other 5 times in 1 hour and 2 times in 1/2 hour
Time duration from 8 am to 9.30 am = 1.5 hour
Hence they cross each other 7 times before 9.30 am

Correct Answer: C. 7 ✔

A. 5 kmph
B. 4 kmph
C. 4.5 kmph
D. 3 kmph

If he travels at 6 kmph,
time taken to reach = 12/6 = 2 hours But he takes 3 hours.
Speed = 12/3 = 4 kmph

Correct Answer: B. 4 kmph ✔

A. 50 km
B. 45 km
C. 40 km
D. 30 km

Correct Answer: B. 45 km ✔

A. 3000m
B. 7500m
C. 3750m
D. 7000m

Average speed for Raj is: v = (2*9*10)/(9+10) = 180/19 km/hr = 50/19 m/s
Average speed for Rohit = 12 km/hr = 10/3 m/s
Now, v = d/t
As d is same, v*t = constant.
Let, t be the time taken by Rohit in seconds. Hence, time taken by Raj is (t +600)s
50/19 * (t + 600) = 10/3 * t
150*(t + 600) = 190t
t = 2250s
Let d be the distance between the house and the office
2d = 2250 * 10/3
2d = 7500 m
d = 3750m

Correct Answer: C. 3750m ✔

A. 660 km/hr
B. 680 km/hr
C. 700 km/hr
D. 720 km/hr

Distance = Speed x Time = 240 x 5 km
New time =5/3 hr

Hence, new speed = Distance/Time =240*5/5/3

=240×3=720 km/hr

Correct Answer: D. 720 km/hr ✔

A. 36
B. 52
C. 41
D. 40

Correct Answer: D. 40 ✔

A. 216 km
B. 240 km
C. 228 km
D. 200 km

Correct Answer: A. 216 km ✔

A. 120 km
B. 100 km
C. 80 km
D. 75 km

Let the speed of the bike be x kmph. Then the speed of the car will be 3x/2 kmph. Time taken by the bike
t1 = 100/x Time taken by the bike
t2 = 100/(3x/2) t1 – t2 = 25/60 (100/x) – (100/(3x/2)) = 5/12 Solving the equation, x = 80 kmph

Correct Answer: C. 80 km ✔

A. 85 miles
B. 70 miles
C. 50 miles
D. 120 miles

Correct Answer: A. 85 miles ✔

A. 47.5
B. 50
C. 45
D. 40

Correct Answer: D. 40 ✔

A. 11.2 kmph
B. 10 kmph
C. 10.2 kmph
D. 10.8 kmph

Correct Answer: D. 10.8 kmph ✔

A. 30 km/hr
B. 35 km/hr
C. 25 km/hr
D. 40 km/hr

Correct Answer: B. 35 km/hr ✔

A. 66 km
B. 55 km
C. 50 km
D. 60 km

Correct Answer: D. 60 km ✔

A. 300 km
B. 290 km
C. 250 km
D. 240 km

Total distance = (120*2) + (100*(1/2)) = 290 km

Correct Answer: B. 290 km ✔

A. 8 kmph
B. 11 kmph
C. 12 kmph
D. 14 kmph

Correct Answer: C. 12 kmph ✔

A. 30 km
B. 40 km
C. 70 km
D. 80 km

Correct Answer: C. 70 km ✔

A. 5 km
B. 5.5 km
C. 6 km
D. 6.5 km

Average speed = ( 2 X 3 X 2/3 + 2 ) km/ hr = 12/5 km/ hr. Distance travelled = ( 12/5 X 5 )km = 12 km. So Distance between house and school = ( 12/2 )km = 6 km.

Correct Answer: C. 6 km ✔

A. 6 hrs 21 min
B. 6 hrs 24 min
C. 6 hrs 27 min
D. 6 hrs 30 min

Time taken to cover 600 km = ( 600/100 ) hrs = 6 hrs. Number of stoppages = ( 600/75 – 1 ) = 7 Total time of stoppage = (3 x 7) min = 21 min. Hence, total time taken = 6 hrs 21 min.

Correct Answer: A. 6 hrs 21 min ✔

A. 7.42 a.m.
B. 7.48 a.m.
C. 8.10 a.m.
D. 8.30 a.m.

Correct Answer: A. 7.42 a.m. ✔

A. 220 km
B. 224 km
C. 230 km
D. 234 km

Correct Answer: B. 224 km ✔

A. 45 metres
B. 55 metres
C. 450 metres
D. Cannot be determined

Correct Answer: C. 450 metres ✔

A. 10 min
B. 11 min 20 sec
C. 13 min
D. 13 min 20 sec

Speed = (10 X 60/12 ) km/hr = 50 km/hr. New speed = (50 – 5) km / hr = 45 km /hr. So Time taken = ( 10/45 ) hr = ( 2/9X 60 )min 131/3 min = 13 min 20 sec.

Correct Answer: D. 13 min 20 sec ✔

A. 1.4
B. 1.5
C. 1.7
D. 1.9

Correct Answer: B. 1.5 ✔

A. 1.4 m
B. 2.8 m
C. 14 m
D. None of these

Correct Answer: D. None of these ✔

A. 12 kg
B. 60 kg
C. 72 kg
D. 96 kg

Volume of water displaced = (3 X 2 X 0.01) m³ = 0.06 m³.
Mass of man = Volume of water displaced X Density of water
= (0.06 X 1000) kg = 60 kg.

Correct Answer: B. 60 kg ✔

A. the volume of the box
B. twice the volume of the box
C. the square of the volume of the box
D. the cube root of the volume of the box

Let length = 1, breadth = b and height = h. Then,
Product of areas of 3 adjacent faces = (lb x bh x 1h) = (lbh)² = (Volume)².

Correct Answer: C. the square of the volume of the box ✔

A. 24 cm³
B. 48 cm³
C. 64 cm³
D. 120 cm³

Let the dimensions of the cuboid be x, 2x and 3x.
Then, 2 (x X 2x + 2x X 3x + x X 3x) = 88
⇔ 2X2 6X2 + 3X2 = 44 ⇔ 11X2 = 44 ⇔ X2 = 4 ⇔ x = 2.
Volume of the Cuboid = (2 X 4 X 6) cm3 = 48 cm³.

Correct Answer: B. 48 cm³ ✔

A. 8
B. 16
C. 27
D. 64

Correct Answer: D. 64 ✔

A. 6
B. 9
C. 24
D. 30

Volume of block = (6 X 9 X 12) cm³ = 648 cm³.
Side of largest cube = H.C.F. of 6 cm, 9 cm, 12 cm = 3 cm.
Volume of this cube = (3 X 3 X 3) = 27 cm³.
Number of cubes = 648/27 = 24.

Correct Answer: C. 24 ✔

A. 12
B. 15
C. 22
D. 20

Work done by P in 1 day = 1/15
Work done by Q in 1 day = 1/10
Work done by P and Q in 1 day = 1/15 + 1/10 = 1/6
Work done by P and Q in 2 days = 2 × (1/6) = 1/3
Remaining work = 1 – 1/3 = 2/3
Time taken by P to complete the remaining work 2/3 = (2/3) / (1/15) = 10 days
Total time taken = 2 + 10 = 12 days

Correct Answer: A. 12 ✔

A. 70
B. 50
C. 40
D. 60

Amount of work done by A and B in 1 day = 1/30

Amount of work done by A and B in 20 days = 20 × (1/30) = 20/30 = 2/3

Remaining work – 1 – 2/3 = 1/3

A completes 1/3 work in 20 days

Amount of work A can do in 1 day = (1/3)/20 = 1/60

=> A can complete the work in 60 days

Correct Answer: D. 60 ✔

A. 18 days
B. 22 ½ days
C. 24 days
D. 26 days

If A completes a work in 1 day, B completes the same work in 3 days

Hence, if the difference is 2 days, B can complete the work in 3 days

=> if the difference is 60 days, B can complete the work in 90 days

=> Amount of work B can do in 1 day= 1/90

Amount of work A can do in 1 day = 3 × (1/90) = 1/30

Amount of work A and B can together do in 1 day = 1/90 + 1/30 = 4/90 = 2/45

=> A and B together can do the work in 45/2 days = 22 ½ days

Correct Answer: B. 22 ½ days ✔

A. 3 hrs.
B. 4 hrs,
C. 5 hrs.
D. 6 hrs.

X’s 1 hour work = 1/10
Y’s 1 hour work = 1/15
(x+y)’s 1 hour work = 1/10+1/15=5/30=1/6
Both the taps can fill the tank in 6 hrs.

Correct Answer: D. 6 hrs. ✔

A. 10 Rs,
B. 15 Rs,
C. 20 Rs.
D. 25 Rs.

B’s daily earning = Rs.(150-94)= Rs.56
A’s daily earning = Rs.(150-76)= Rs.74
C’s daily earning = Rs.[(150-(56+74)]=Rs.20

Correct Answer: C. 20 Rs. ✔

A. 12 days
B. 14 days
C. 16 days
D. 18 days

3 men does same work as 4 women in 43 days.

multiply 3 and 4 and 43 for a supposed amount of total work (516).

Now calculate how much work is done by 3 men in one day by dividing 516 by 43 (12). Then calculate one man work in one day by dividing 12 by 3 (4).

Same (12) amount of work is done by 4 women in one day. so one women does 12/4 (3) in one day.

now see there are 7 men and 5 women in the final team.
total amount of work in one day will be

7(4)+5(3) = 43

Now divide total work (516) by total work in one day (43) to get the answer (12)

Correct Answer: A. 12 days ✔

A. 1.8 days
B. 1.5 days
C. 1.2 days
D. 1 day

Time is
directly proportional to number of sofas
inversely proportional to number of people No. of days
= (6/8)*(8/10)*2
= 1.2 days

Correct Answer: C. 1.2 days ✔

A. 1
B. 5
C. 10
D. 25

10 workers make 10 tables in 10 days. 1 worker makes 1 table in 10 days. Similarly, 5 workers can make 5 tables in 10 days.

Correct Answer: C. 10 ✔

A. 2 men
B. 12 men
C. 9 men
D. 18 men

For the work to be completed in 9 days,
6 men are required. Time and men are inversely proportional. For the work to be completed in 3 days,
6*9/3 = 18 men are required

Correct Answer: D. 18 men ✔

A. Rs.1104
B. Rs.1000
C. Rs.934
D. Rs.1210

Assume that cost of keeping a cow for 1 day = c ,

cost of keeping a goat for 1 day = g
Cost of keeping 20 cows and 40 goats for 10 days = 460

Cost of keeping 20 cows and 40 goats for 1 day = 460/10 = 46

=> 20c + 40g = 46

=> 10c + 20g = 23 —(1)

Given that 5g = c
Hence equation (1) can be written as 10c + 4c = 23 => 14c =23

=> c=23/14
cost of keeping 50 cows and 30 goats for 1 day

= 50c + 30g

= 50c + 6c (substituted 5g = c)

= 56 c = 56×23/14

= 92
Cost of keeping 50 cows and 30 goats for 12 days = 12×92 = 1104

Correct Answer: A. Rs.1104 ✔

A. 7
B. 8
C. 9
D. 6
Let P takes x days to complete the work
Then Q takes x/2 days and R takes x/3 days to finish the work
Amount of work P does in 1 day = 1/x
Amount of work Q does in 1 day = 2/x
Amount of work R does in 1 day = 3/x
Amount of work P,Q and R do in 1 day = 1/x + 2/x + 3/x = 1/x (1 + 2 + 3) = 6/x
6/x = 2
=> x = 12
=> Q takes 12/2 days = 6 days to complete the work

Correct Answer: D. 6 ✔

A. 50
B. 30
C. 40
D. 13

Work done by 4 men and 6 women in 1 day = 1/8
Work done by 3 men and 7 women in 1 day = 1/10
Let 1 man does m work in 1 day and 1 woman does w work in 1 day. The above equations can be written as
4m + 6w = 1/8 —(1)
3m + 7w = 1/10 —(2)
Solving equation (1) and (2) , we get m=11/400 and w=1/400
Amount of work 10 women can do in a day = 10 × (1/400) = 1/40
Ie, 10 women can complete the work in 40 days

Correct Answer: C. 40 ✔

A. 10 days
B. 14 days
C. 15 days
D. 9 days

Correct Answer: C. 15 days ✔

A. 10 min
B. 20 min
C. 30 min
D. 40 min

Correct Answer: B. 20 min ✔

A. 15 days
B. 14 days
C. 16 days
D. 30 days

Raio of times taken by A and B = 1 : 3
If the difference of time is 2 days, B takes 3 days. If the difference of time is 10 days.
B takes [3/2×10]=15 days

Correct Answer: A. 15 days ✔

A. 6 days
B. 8 days
C. 10 days
D. 12 days

2 children = 1 man
(8 children + 12 men ) = 16 men
Now, less men, more days
12 : 16 : 9 : x
x = 16×9/12=12 days

Correct Answer: D. 12 days ✔

A. 48 days
B. 24 days
C. 40 days
D. 36 days

No. of days is
directly proportional to the length of the wall and
inversely proportional to the number of men No. of days = (1200/500)*(15/30)*30 = 36 days

Correct Answer: D. 36 days ✔

A. 24 days
B. 14 days
C. 15 days
D. 20 days

Time and Men are inversely proportional. Time taken by 28 men to finish the work = 15 days Time taken by a man to finish the work
= 15*28 days Time taken by 21 men = (15*28)/21 = 20 days

Correct Answer: D. 20 days ✔

A. 10 days
B. 12 days
C. 8 days
D. 9 days

Part of work completed by C in 1 day = 1/12 Part of work completed by D in 1 day = 1/15 Part of work completed by C in 4 days
= 1/3 Work remaining = 2/3 Time taken by D to complete the work
= (2/3)÷(1/15) = 10 days

Correct Answer: A. 10 days ✔

A. Rs.40
B. Rs.70
C. Rs.90
D. Rs.100

Amount Earned by P,Q and R in 1 day = 1620/9 = 180 —(1)
Amount Earned by P and R in 1 day = 600/5 = 120 —(2)
Amount Earned by Q and R in 1 day = 910/7 = 130 —(3)
(2)+(3)-(1) => Amount Earned by P , Q and 2R in 1 day
– Amount Earned by P,Q and R in 1 day = 120+130-180 = 70
=>Amount Earned by R in 1 day = 70

Correct Answer: B. Rs.70 ✔

A. 5 days
B. 10 days
C. 15 days
D. 12 days

Work done by P in 1 day = 1/20
Work done by Q in 1 day = 1/12
Work done by P in 4 days = 4 × (1/20) = 1/5
Remaining work = 1 – 1/5 = 4/5
Work done by P and Q in 1 day = 1/20 + 1/12 = 8/60 = 2/15
Number of days P and Q take to complete the remaining work = (4/5) / (2/15) = 6
Total days = 4 + 6 = 10

Correct Answer: B. 10 days ✔

A. 8
B. 6
C. 4
D. 2

Work done by P in 1 day = 1/18
Work done by Q in 1 day = 1/15
Work done by Q in 10 days = 10/15 = 2/3
Remaining work = 1 – 2/3 = 1/3
Number of days in which P can finish the remaining work = (1/3) / (1/18) = 6

Correct Answer: B. 6 ✔

A. 9(3/5) days
B. 9(1/5) days
C. 9(2/5) days
D. 10 days

Amount of work P can do in 1 day = 1/16
Amount of work Q can do in 1 day = 1/12
Amount of work P, Q and R can together do in 1 day = 1/4
Amount of work R can do in 1 day = 1/4 – (1/16 + 1/12) = 3/16 – 1/12 = 5/48
=> Hence R can do the job on 48/5 days = 9 (3/5) days

Correct Answer: A. 9(3/5) days ✔

A. 12 hrs
B. 14 hrs
C. 16 hrs
D. 18 hrs

Explanation:
Part filled in 10 hrs.
= 10[1/15+1/20−1/25]=23/30

Correct Answer: A. 12 hrs ✔

A. 12 days
B. 16 days
C. 18 days
D. 20 days

Correct Answer: B. 16 days ✔

A. 85 days
B. 126 days
C. 118 days
D. 136 days

Time taken is inversely proportional to their efficiency. So, time taken is in the ratio 8:5. Time taken by Rashid to finish the work = 8x Time taken by Danish to finish the work = 5x 8x-5x=51 3x=51 x=17 8x=136

Correct Answer: D. 136 days ✔

A. 16
B. 4
C. 12
D. 8

12 men work 8 hours for 10 days x men work 12 hours for 5 days x = (12*8*10)/(12*5) = 16 men

Correct Answer: A. 16 ✔

A. 15
B. 14
C. 16
D. 13

Correct Answer: C. 16 ✔

A. 7 hour 15 minutes
B. 7 hour 30 minutes
C. 8 hour 15 minutes
D. 8 hour 30 minutes

Pages typed by Mansoor-Ul-Haque in 1 hour = 32/6 = 16/3
Pages typed by Aaqib in 1 hour = 40/5 = 8
Pages typed by Mansoor-Ul-Haque and Aaqib in 1 hour = 16/3 + 8 = 40/3
Time taken to type 110 pages when Mansoor-Ul-Haque and Aaqib work together = 110 × 3 /40 = 33/4
= 8 ¼ hours = 8 hour 15 minutes

Correct Answer: C. 8 hour 15 minutes ✔

A. 3 pm
B. 2 pm
C. 1:00 pm
D. 11 am

Work done by P in 1 hour = 1/8
Work done by Q in 1 hour = 1/10
Work done by R in 1 hour = 1/12
Work done by P,Q and R in 1 hour = 1/8 + 1/10 + 1/12 = 37/120
Work done by Q and R in 1 hour = 1/10 + 1/12 = 22/120 = 11/60
From 9 am to 11 am, all the machines were operating.
Ie, they all operated for 2 hours and work completed = 2 × (37/120) = 37/60
Pending work = 1- 37/60 = 23/60
Hours taken by Q an R to complete the pending work = (23/60) / (11/60) = 23/11
which is approximately equal to 2
Hence the work will be completed approximately 2 hours after 11 am ; ie around 1 pm

Correct Answer: C. 1:00 pm ✔

A. 8/15
B. 7/15
C. 11/15
D. 2/11

Amount of work P can do in 1 day = 1/15
Amount of work Q can do in 1 day = 1/20
Amount of work P and Q can do in 1 day = 1/15 + 1/20 = 7/60
Amount of work P and Q can together do in 4 days = 4 × (7/60) = 7/15
Fraction of work left = 1 – 7/15= 8/15

Correct Answer: A. 8/15 ✔

A. 30 min
B. 35 min
C. 40 min
D. 45 min

Correct Answer: D. 45 min ✔

A. 40 days
B. 50 days
C. 60 days
D. 70 days

(A+B)’S 1 day’s work = [1/15−1/20]=1/60
A alone can finish it in 60 days

Correct Answer: C. 60 days ✔

A. 50
B. 75
C. 60
D. 45

Part of work completed by Farjan and Kashif in a day
= 1/30 Part of work completed by them in 20 days
= 20/30 = 2/3 1/3 of the work is remaining. Kashif completes 1/3rd of the work in 25 days. Part of work completed by him in a day
= (1/3)÷25
= 1/75 (1/D)+(1/V) = 1/30 (1/D) = (1/30)-(1/75) = 1/50 Farjan can complete it in 50 days.

Correct Answer: A. 50 ✔

A. 12:00 pm
B. 2:00 am
C. 12:00 am
D. 10:00 pm

Jameel works for 5 hours. So he completes 5/15 = 1/3 of the task Nasir has to complete 2/3rd of the task 12*2/3 = 8 hours are needed. He completes the task at 12:00 am.

Correct Answer: C. 12:00 am ✔

A. 10
B. 9
C. 11
D. 12

Work done by P in 1 day = 1/24
Work done by Q in 1 day = 1/9
Work done by R in 1 day = 1/12
Work done by Q and R in 1 day = 1/9 + 1/12 = 7/36
Work done by Q and R in 3 days = 3×7/36 = 7/12
Remaining work = 1 – 7/12 = 5/12
Number of days in which P can finish the remaining work = (5/12) / (1/24) = 10

Correct Answer: A. 10 ✔

A. 14
B. 16
C. 15
D. 11

Work done by Kamal in 1 day = 1/20
Work done by Suresh in 1 day = (1/20) × (125/100) = 5/80 = 1/16
=> Suresh can complete the work in 16 days

Correct Answer: B. 16 ✔

A. 37 ½ days
B. 22 days
C. 31 days
D. 22 days

Work done by A in 20 days = 80/100 = 8/10 = 4/5

Work done by A in 1 day = (4/5) / 20 = 4/100 = 1/25 — (1)

Work done by A and B in 3 days = 20/100 = 1/5 (Because remaining 20% is done in 3 days by A and B)

Work done by A and B in 1 day = 1/15 —(2)

Work done by B in 1 day = 1/15 – 1/25 = 2/75

=> B can complete the work in 75/2 days = 37 ½ days

Correct Answer: A. 37 ½ days ✔

A. 14
B. 15
C. 16
D. 18

Capacity of the tank = (12×13.5)=162 litres
Capacity of each bucket = 9 litres.
Number of buckets needed = 162/9=18

Correct Answer: D. 18 ✔

A. 12,342 litres.
B. 12,444 litres
C. 12,566 litres.
D. None of thes

Correct Answer: A. 12,342 litres. ✔

A. 75/8 days
B. 44/6 days
C. 48/5 days
D. None of these

Correct Answer: A. 75/8 days ✔

A. 12
B. 8
C. 10
D. 9

Part of work completed by A in a day = 1/X Part of work completed by B in a day
= 1/(X+5) (1/X)+(1/(X+5)) = 1/6 (2X+5)/(X²+5X) = 1/6 X²+5X = 6(2X+5) X²-7X-30=0 Solving, X=10

Correct Answer: C. 10 ✔

A. 2700
B. 1080
C. 450
D. 1800

Number of bottles produced by 1 machine in a minute
= 270/6 Number of bottles produced by 10 machines in 4 minutes
= (270/6)*10*4 = 1800

Correct Answer: D. 1800 ✔

A. 7
B. 8
C. 9
D. 10

Let work done by P in 1 day = p
work done by Q in 1 day =q
Work done by R in 1 day = r
p + q = 1/8 —(1)
q + r= 1/12 —(2)
p+ q+ r = 1/6 —(3)
(3) – (2) => p = 1/6 – 1/12 = 1/12
(3) – (1) => r = 1/6 – 1/8 = 1/24
p + r = 1/12 + 1/24 = 3/24 = 1/8
=> P and R will finish the work in 8 days

Correct Answer: B. 8 ✔

A. 7
B. 5
C. 6
D. 4

Work done by 10 men in 1 day = 1/7
Work done by 1 man in 1 day = (1/7)/10 = 1/70
Work done by 10 women in 1 day = 1/14
Work done by 1 woman in 1 day = 1/140
Work done by 5 men and 10 women in 1 day = 5 × (1/70) + 10 × (1/140)
= 5/70 + 10/140 = 1/7
=> 5 men and 10 women can complete the work in 7 days

Correct Answer: A. 7 ✔

A. 30 days
B. 25 days
C. 20 days
D. 15 days

Work done by P and Q in 1 day = 1/10
Work done by R in 1 day = 1/50
Work done by P, Q and R in 1 day = 1/10 + 1/50 = 6/50
But Work done by P in 1 day = Work done by Q and R in 1 day . Hence the above equation can be written as
Work done by P in 1 day × 2 = 6/50
=> Work done by P in 1 day = 3/50
=> Work done by Q and R in 1 day = 3/50
Hence work done by Q in 1 day = 3/50 – 1/50 = 2/50 = 1/25
So Q alone can do the work in 25 days

Correct Answer: B. 25 days ✔

A. 5,750 litres
B. 5,760 litres
C. 6,890 litres
D. None of these

Correct Answer: B. 5,760 litres ✔

A. 12 min
B. 14 min
C. 16 min
D. 20 min

In this problem, rate of water pipe (waste) is more, the tank will be emptied when the pipes are opened.
Work done in total emptying in 1 min.
=1/16−1/32=1/32
Now, full tank will be emptied by them in 32 minutes.
Half full tank will be emptied in 16 minutes.

Correct Answer: C. 16 min ✔

A. 20 days
B. 30 days
C. 40 days
D. none of these

Correct Answer: B. 30 days ✔

A. 3:4
B. 5:4
C. 4:3
D. 5:3

Part of work completed by a man in a day = 1/(12*20)
= 1/240 Part of work completed by a woman in a day = 1/(20*16) = 1/320 Ratio of their capacities
= (1/240):(1/320) = 320:240 = 4:3

Correct Answer: C. 4:3 ✔

A. 4
B. 9.6
C. 9
D. 10

Part of work completed by A and B in 4 days
= 4*((1/16) + (1/12))
= 7/12 C can complete 5/12th of the work in 4 days C can complete the whole job in
4÷(5/12) = 9.6 days

Correct Answer: B. 9.6 ✔

A. 2
B. 8
C. 10
D. 12

M1*D1*W2 = M2*D2*W1
10*3*10*32 = 30*d*8*20
d = 2 days

Correct Answer: A. 2 ✔

A. 1:3
B. 4:3
C. 2:3
D. 2:1

Work done by 20 women in 1 day = 1/16

Work done by 1 woman in 1 day = 1/(16×20)
Work done by 16 men in 1 day = 1/15

Work done by 1 man in 1 day = 1/(15×16)
Ratio of the capacity of a man and woman =1/(15×16) : 1/(16×20) = 1/15 : 1/20

= 1/3 :1/4 = 4:3

Correct Answer: B. 4:3 ✔

A. 2
B. 3 3⁄7
C. 4 ¼
D. 5

Work done by P in 1 day = 1/24
Work done by Q in 1 day = 1/6
Work done by R in 1 day = 1/12
Work done by P,Q and R in 1 day = 1/24 + 1/6 + 1/12 = 7/24
=> Working together, they will complete the work in 24/7 days = 3 3⁄7 days

Correct Answer: B. 3 3⁄7 ✔

A. 2 min
B. 3 min
C. 4 min
D. 5 min

Let Q be closed after x min.  Then part filled by (P+Q) in x min + part filled by P in ( 9 – x )min
x(1/12+1/16)+(9−x)1/12=1

Correct Answer: C. 4 min ✔

A. 12/6 days
B. 15/2 days
C. 23 days
D. 34 days

Ratio of time, taken by A and B = 160 : 100 = 8 : 5
If A takes 8 days, B takes 5 days.
If A takes 12 days, B takes = [5/8×12]=15/2 days

Correct Answer: B. 15/2 days ✔

A. 70 days
B. 120/7 days
C. 50 days
D. 45 days

Correct Answer: B. 120/7 days ✔

A. 5
B. 6
C. 7
D. 8

Part of work completed by A in a day = 1/21 Part of work completed by B in a day = 1/24 Part of work completed by them together in a day = (1/21)+(1/24)
= 5/56 Part of work completed by B in 9 days
= 9/24 = 3/8 If A left after x days,
(5x/56)+(3/8) = 1
x = 7

Correct Answer: C. 7 ✔