Rekha alone can complete a work in 16 days, and Bina alone can complete the same work in 12 days. Starting with Rekha, they work on alternate days. The total work will be completed in:
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 13 days.
Let the total work of 16 and 12 days is = 48 units (LCM of 16 and 12)
The efficiency of Rekha is = 48 / 16 = 3 units
The efficiency of Bina is = 48 / 12 = 4 units
Total work done in 2 days = 3 + 4 = 7 units
42 units of work done by Rekha and Bina = 6 × 2 = 12 days
Rekha does in 1 day = 3 units
Bina does in 1 day = 4 units
Hence
Bina does 3 units in = 3/4 days
Total number of days = 12 + 1 + 3/4 = 13days