Question

A takes twice as much time as B and C together take to finish the job. A and B working together finish the job in 4 days. C alone can do the same job in 4 days. In how many days can B alone do the same job?​

Answer 1

Answer:

6 days

Step-by-step explanation:

Let the number of days taken by B to finish the work be x

Then, in 1 day he finishes 1/x part of the work

According to the question, A takes twice as much time as B = 2(x) = 2x

Then, in 1 day A can finish 1/2x part of the work.

A and B working together can finish the work in 4 days.

so, in one day, A and B working together can finish 1/4 part of the work.

1/x+1/2x = 1/4

2+1/2x = 1/4 (2x is common)

3/2x = 1/4

2x = 4*3 (by cross multiplication)

2x = 12

x = 12/2 = 6.

so B takes 6 days to complete the full work, A takes 12 days and C takes 4 days to complete.