Ramu works 4 times as fast as Somu. If Somu can complete a work in 20 days independently, then the number of days in which Ramu and Somu together can complete the work is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e 4 days
Somu, can complete the work in = 20 days
Ramu, can do 4 times faster so will take (1 / 4) time
Ramu will complete work independently = 20 / 4 = 5 days
They would take days together ⇒ (1 / 20) + (1 / 5)
⇒ (1 + 4) / 20
⇒ 1 / 4
The number of days the would take to work together = 4