A and B can do a job together in 7 days. A is 1 3/4 times as efficient as B. The same job can be done by A alone in:
Answer: B
A is 7/4 times as efficient as B. The ratio of their efficiencies A:B is 7:4. Combined efficiency = 11 units (say). Total work = \(11 \times 7 = 77\) units. Time for A alone = Total work / A's efficiency = 77 / 7 = 11 days.