Question

B is 20% more efficient than A. B started the work & do it for
x days. And then B is replaced by A, A completed the
remaining work in `x+8` days. Ratio of work done by A & B is
3:2 IN how many days A & B working together complete
the whole work?
A. ` 13 11/17 days`
B. ` 12 7/11 days`
C. ` 13 7/11 days`
D. ` 12 8/13 days `

Answer 1

Correct Answer - (c)
Efficiency ratio A and ` B = 5:6`
And time ratio A and `B = 6 : 5`
i.e. in 1 day A and B together do 6 + 5 = 11 units work
Now,
`("Work done by B")/("Work done by A") = (6xx x)/ (5xx(x+8) = 2/3`
`x=10`
B does ` 10 xx 6 = 60` units work
A does `(10 + 8)xx 5 = 90` units work
So, total work i.e. `60+90 = 150` units will be completed
by A and B together inn `150/11 i.e. 13 7/11` days