A is twice as good a workman as B and together they finish a piece of work in 13 days, In how many days will B alone finish the work?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 39
A is twice as good a workman as B and together they finish a piece of work in 13 days.
Efficiency is inversely proportional to Time.
The efficiency ratio of A and B is 2 : 1.
The time ratio of A and B is 1 : 2.
Let, A take time x days, and B took time 2x days to complete the work alone.
In 1 day A can do 1/x part of the work.
In 1 day B can do 1/2x part of the work.
Together in 1 day, they can do 1/13 part of the work.
(1/x) + (1/2x) = 1/13
3/2x = 1/13
x = 39/2
B alone will finish the work in = 2 × (39/2)= 39 days