A can do 60% of a work in 18 days, while B can do 40% of the same work in 10 days. Both work together for 10 days only. C complete the remaining work in 4 days. In how many days will C complete the same work?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 15 days.
Concept Used:
Total work = Efficiency × total time
Explanation:
According to the given question,
A can do 60% of a work in 18 days
⇒ A can do 100% work in 30 days
B can do 40% of the work in 10 days
⇒ B can do 100% work in25 days
Let the total work to be completed is LCM(30, 25) = 150 units
Now, efficiency of A = = 5 units/day
Also, efficiency of B = = 6 units/day
Now tota work done by (A + B) in 10 days = (5 + 6) × 10 = 110 units
Remaining work = 150 - 110 = 40 units
So, efficiency of C = = 10 units/day
Number of days taken by C to complete the whole work = = 15 days
Hence the required answer is 15 days.