Question

A does half of the work in 1 hour as much as B does in 3/4 hours.
If together they take 18 hours, then B can finish the work alone in how many hours.

Answer 1

Answer:

B alone can finish the work in 30 hours.

Step-by-step explanation:

Let the number of hours taken by B alone to finish the work be x.

So number of hours taken by A alone to finish half of the work = 3x/4.

So number of hours taken by A alone to finish the work = 2 × (3x/4)= 3x/2.

Number of hours taken by both to finish the work =18.

part of work done by both in 1 hour = 1/18

Part of work done by A alone in 1 hour =1/(3x/2) = 2/3x.

Part of work done by B alone in 1 hour = 1/x.

So 1/x + 2/3x = 1/18 => (3+2)/3x = 1/18

5/3x = 1/18 => 3x = 5×18 => x = 5×18/3= 30

So number of hours taken by B alone = 30