Question

‘X’ and ‘Y’ together can complete a work in 10 days, while ‘Y’ and ‘Z’ together can complete the work in 8 days. If ‘Y’ takes 12 days to complete the work alone then find the approximate time taken by all three together to complete 65% of work.

A 3 days Correct Answer Incorrect Answer
B 7 days Correct Answer Incorrect Answer
C 9 days Correct Answer Incorrect Answer
D 5 days Correct Answer Incorrect Answer
E 6 days Correct Answer Incorrect Answer

Solution

Let the total work = 120 units
Efficiency of (X + Y) = 120/10 = 12 units/day
Efficiency of (Y + Z) = 120/8 = 15 units/day
Efficiency of ‘Y’ = 120/12 = 10 units/day
Efficiency of (X + Y + Z) = (12 + 15 – 10) = 17 units/day
Required time taken = (0.65 × 120)/17 = 5 days (approx)

Practice Next

Relevant for Exams:

×
×