Question

a can do a piece of work in 15 days he dose the work for 3 days only and leaves the job. b disr the remaining work in 8 days in how many days b alone can do the work​

Answer 1

A can do a work in 15 days

So in one day, A can do 1/15 th of total work.

In 8 days, A did 1/15 * 8 = 8/15 th of total work.

Remaining work 1 - 8/15 = 7/15

A+B did 7/15 th work in 4 days

Out of 7/15 , 4/15 th work was done by A

So all in all, in 4 days, B did 3/15 th of total work.

And in one day B can do 3/60 th of total work.

So, B will require 60/3 =20 days to complete the work alone.

Answer 2

The answer is 10 days

GIVEN

A can do a piece of work in 15 days he dose the work for 3 days only and leaves the job. B does the remaining work in 8 days.

TO FIND

B alone can do the work in how many days.

SOLUTION

The above problem can be simply solved as follows;

Time taken by A = 15 days

A's one day work = 1/15

A's 3 days work = (1/15) × 3 = 1/5

Remaining work = 1 - 1/5

= 4/5

Therefore,

B takes 8 days to complete 4/5th of work

Let B takes x days to complete the whole work

Therefore,

4/5 of x = 8

4x = 40

x = 10

Hence, The answer is 10 days

#SPJ3