A can do a certain piece of work in 1.5 times the number of days in which B and C together can do it. If A and B together can do the said piece of work in 30 days and C alone can do it in 120 days, then how many days will B take to do this piece of work alone?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 60.
Ratio of Time
A : (B + C) = 1.5/1 = 3/2
So, the Ratio of efficiency
A : (B + C) = 2/3
Let's assume the total work = LCM of 30 and 120 = 120 unit
Efficiency of (A + B) = 120/30 = 4 unit/day, Efficiency of C = 120/120 = 1 unit/day
So, the efficiency of B = 4 - 2 = 2 unit/day
Time taken by B to complete the work = 120/2 = 60 days