3. A can do a piece of work in 6 days. B is 50% more efficient. The number of days it take B to do work is

A. 9
B. 3
C. 2
D. 4

Is the answer 4? If so, how did you get your answer?

3 answers

3/2 as productive means it takes 2/3 as much time. So, (D).
What do you mean?
Looks like you need to study what 50% more efficient means. It means B can do 50% more work than A in a given time.

50% = 0.5

So, 50% more means 1.5 times as much. That's 3/2.

Think about it. If I do twice as much as you, it takes half (1/2) as long.

If I do 3/2 as much as you, it takes 1 /(3/2) = 2/3 as long.