Question

Efficiency of A is twice more than that of B. If B takes 28 days more to finish a work, In how many days; (A + B) will complete the whole work?

• A. 11 days
• B. 10.5 days
• C. 10 days
• D. 11.5 days

Answer 1

Answer:

B. 10.5 days

Efficiency ratio A : B = 3 : 1 Time ratio A : B = 1 : 3 difference in ratio, 2 → 28 days 1 → 14 days A takes 14 days to complete the work alone B takes 3 × 14 = 42 days to complete the work alone total work = LCM(14,42) = 42 (A + B) together will complete the work in 42/(3 + 1) = 10.5 days