Ronak and Riya can do a work in 12 and 18 days, respectively. They worked together for six days and then Ronak left. Find the time taken by Riya to complete the work.
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 3 days
Ronak and Riya can do a work in 12 and 18 days, respectively.
Total work = L.C.M of 12 and 18 = 36 units
Amount of work done by Ronak in a day = 36/12 = 3 units
Amount of work done by Riya in a day = 36/18 = 2 units
Amount of work done by them in a day together = 3 + 2 = 5 units
Amount of work done by them in 6 days = 6 × 5 = 30 units
Amount of work to be completed alone by Riya = 36 - 30 = 6 units
Time taken by Riya to complete the work = 6/2 = 3 days