Ramesh and Rahman can do a work in 20 and 25 days respectively. After doing collectively 10 days of work, they leave the work due to illness and Suresh completes rest of the work in 3 days. How many days Suresh alone can take to complete the whole work?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e 30 days
LCM of (20, 25)
LCM = 100 units
In 10 days, they together do = (5 + 4) × 10 = 90 days
Reamining units (100 - 90) = 10 days
Suresh completes 10 units in 3 days
his work efficiancy = 10/3 unit/day
Suresh alone can do work in 10/(10/3) = 30 days