Question

if *a* alone can do a work in 8 days and *a* and *b* can do a work in 6 days. in how many days can *b* do a work.
please help me as quick as possible I have my exam tomorrow.

Answer 1

a -> 8 days to do a work
In 1 day, he can do: 1/8 of the total work

Let b can do a work in x days
in one day, 1/x

together, they can do it in 6 days
in one day, 1/6
add one day work of a and b
1/8 + 1/x = 1/6

1/x = 1/24
x = 24 days