To do a certain work, A is 40% more efficient than B. Working together; they can do the same work in 15 days. A started the work and left after 15 days. B and C together completed the remaining work in the next 10 days. C alone can do one-third of the original work in:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 24 days.
Efficiency ratio (A : B) = 140 : 100 = 7 : 5
Total work = (7 + 5) × 15 = 180
A’s work = 7 × 15 = 105
Remaining work = 180 - 105 = 75
Combined efficiency of (B + C) = 75/10 = 7.5
B’s efficiency = 5
C’s efficiency = 7.5 - 5 = 2.5
Time for C to do 1/3 of work = (180/3)/2.5 = 60/2.5 = 24 days