A. 18 hrs
B. 16 hrs
C. 15 hrs
D. 12 hrs
Explanation:
1/20 + 1/30 = 1/12
1 + 1/3 = 4/3
1 — 12
4/3 — ?
4/3 * 12 = 16 hrs
Correct Answer: 16 hrs ✔
Last Updated: February 08, 2020
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