If the time taken by A is 9 hours more than time taken by A + B together and B takes 36 hours more than the time taken by A + B together, find the time taken by B to finish the work.
Answer & explanation
Correct answer: option 1
Let A + B takes x hours to complete the work
then A takes x + 9 hours
and B takes x + 36 hours
by the formula x= geometric mean of 9 and 36 i.e. x2 = 9 × 36
x = 18
Then A takes 9 + 18= 27 hours
and B takes 9 + 36 = 45 hours