Question

A can do a job in 18 days and b can do it in 30 days. a and b working together will finish twice the amount of work in ------- days?

Answer 1

a and b completed work is 11 1/4

Answer 2

Given :

• Time taken by A = 18days
• Time taken by B = 30days

To Find :-

Number of days required to complete double work when they work together.

Solution:-

Total work = L.C.M(18,30)

Total work = 90

Efficiency of A = 90/18

Efficiency of A = 5

Similarly;

Efficiency of B = 90/30

Efficiency of B = 3

According to Question :-

Twice of the given work will be = 2×90 = 180

Total time taken by A +B to complete the work = 180/8

Total time taken by A +B to complete the work = 180/8 = 45/2 = 22.5 days

Hence :-

The required answer is 22.5 days.