A and B together can paint a wall in 3 days. A can do it alone in 5 days. How many days would it take B to do this job alone?

A and B together can paint a wall in 3 days. A can do it alone in 5 days. How many days would it take B to do this job alone? Correct Answer 7.5

A and B together in 1 day can paint  1/3 of the wall A alone in 1 day can paint 1/5 of the wall Then, B alone can paint (1/3 - 1/5 = 2/15) of the wall in 1 day So, B alone can paint the wall in 15/2 = 7.5 days
Bissoy MCQ

Related Questions