A takes four times as much as B and thrice as much as C to finish a piece of work. If they work together, they finish the work in 24 days. Which of the following is true?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. B is most efficient; takes 48 days.
Ratio of time taken by A and B = 4 : 1
Ratio of time taken by A and C = 3 : 1
Ratio of time taken by B, A and C = 3 : 12 : 4
Ratio of efficiencies of B, A and C = 4 : 1 : 3
Let the efficiencies of A, B and C be x, 4x and 3x respectively.
Total work done = (4x + 1x + 3x) × 24 = 192x units
Time taken by A = 192x/x = 192 days
Time taken by B = 192x/4x = 48 days
Time taken by C = 192x/3x = 64 days
So, B is most efficient; takes 48 days.