# In How Much Time They can do it Together? if

A is thrice as good a workman as B and is therefore able to finish a piece of work in 60 days less than B. Find the time in which they can do it, working together.

- 23/2 days
- 45/2 days
- 21 days
- 25 days

**Answer: (2) 45/2 days**

**Explanation:-**

Let the B can complete the work = X days

Then, A can complete the work = (X – 60 ) days

The ratio of work done by A and B = 3 : 1

Then,

(X – 60 )/X = 1/3

By cross multiplication,

3 X – 3 x 60 = X

3 X – X = 180

2 X = 180

X = 180/2

X = 90

Therefore, time taken by B to complete the work = 90 days

Then, time taken by A to complete the work = 90 /3

= 30 days

A & B work together ,

Then, they will complete the work = 90 x 30/(90 + 30)

= 2700/120

= 45/2 days

Hence, the answer is (2) 45/2 days.