Efficiency of Ritu is 60% more than Rakesh and difference between the number…
2022
Efficiency of Ritu is 60% more than Rakesh and difference between the number of days taken by them to complete a work in 18 days. If efficiency of Rahul is 12.5% less than Ritu, then find the time taken by all the three to together to complete the work.
Answer: B. 12 days — Let Rakesh's efficiency be 10 units/day. Ritu is 60% more efficient, so her efficiency is 16 units/day. Their time ratio is inverse to efficiency, so…
- A.
10 days
- B.
12 days
- C.
9.5 days
- D.
7 days
- E.
5.5 days
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Correct answer: B
Let Rakesh's efficiency be 10 units/day. Ritu is 60% more efficient, so her efficiency is 16 units/day.
Their time ratio is inverse to efficiency, so Rakesh:Ritu time = 8:5. The difference of 3 ratio-parts equals 18 days, so one part is 6 days.
Rakesh takes 48 days and Ritu takes 30 days. Total work = 10 x 48 = 480 units.
Rahul is 12.5% less efficient than Ritu, so Rahul's efficiency is 14 units/day.
Combined efficiency = 10 + 16 + 14 = 40 units/day. Time together = 480/40 = 12 days.