Question

A can complete a certain job in 12 days. B is 60% more efficient than A. In how many days can B complete the same job?

Answer 1

b will complete the work in 4.8days

Answer 2

B is 60% more efficient than A, means that the rate of B is 1.6 times as greater as that of A

So if A can complete the job in 12 days, then B complete the same job in 12/1.6 = 12/(8/5) = 15/2 = 7.5 days.