A. 81 min
B. 108 min
C. 144 min
D. 192 min
Explanation:
Let the slower pipe alone fill the tank in x min.
Then, faster pipe will fill it in x/3 min.
1/x + 3/x = 1/36
4/x = 1/36 => x = 144 min.
Correct Answer: 144 min ✔
Last Updated: February 08, 2020