316 views

A can complete a piece of work in $4$ days. B takes double the time taken by A, C takes double that of B, and D takes double that of C to complete the same task. They are paired in groups of two each. One pair takes two thirds the time needed by the second pair to complete the work. Which is the first pair?

1. A, B
2. A, C
3. B, C
4. A, D

Time taken by A to complete a work=4 days

Time taken by B to complete a work=8 days

Time taken by C to complete a work=16 days

Time taken by D to complete a work=32 days

Time taken by pair (A,D) to complete a work=4 + 32=-36 days

Time taken by pair (B,C) to complete a work=8 +16 =24 days

(B,C) takes two thirds  time Taken by (A,D) to complete the work.

Time taken by (B,C)= $\frac{2}{3}*36=24$

11.1k points

1