In a factory, a piece of work is completed by Raima in 15 days while John can finish it in 10 days. The factory manager has to complete the work as soon as possible so he orders John and Raima to work together. How many days will it take to complete the work?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is Option 4 i.e. 6.
A piece of work is completed by Raima in 15 days while John can finish it in 10 days.
Let x be the number of days taken when they work together
⇒ 1/x = 1/15 + 1/10
⇒ 1/x = (2 + 3)/30
⇒ 1/x = 5/30
⇒ x = 30/5 = 6 days