Question

Adrian can do a piece of work in 20 days and Brody can do the same piece of work in 15 days. With the help of Collin , they completed the work in 8 days. How much time will Collin alone take to finish it?​

Answer 1

Answer:

Correct option is

D

421

Given A can do the work in 20 days and B can do it 15 days.

Then work done by A in one day =201

And, work by B in one day =151

Then, the work done by A & B in one day =201+151=607

A & B done 6 days together then work done in A & B in 6 days =607×6=107

Then friction of work left =1−107=103

Then B can  do  103  work =103×115=29=421 days.