Correct Answer - Option 4 : 560/37
Given:
Ambika, Amba, and Ambalika complete a piece of work in = 6 days
Amba can alone complete the work in = 35 days
Ambika takes = 15 days less than Amba
Calculation:
Ambika + Amba + Ambalika = 6 days
Amba = 35 days
∴ Ambika = 35 - 15
⇒ 20 days
Let the total units of work be 420 units
∴ (Ambika + Amba + Ambalika)’s one day’s work = 70 units
∴ Ambika’s one day work = 21 units
∴ Amba = 12 units
∴ Ambalika’s one day work = 70 – 33
⇒ 37 units
Ambalika’s efficiency to do the work alone
⇒ 75/100 × 37
Time required to complete the work
⇒ (420 × 4)/(37 × 3)
⇒ 560/37 days
Ambalika completes the whole work alone with 75% of his efficiency in 560/37 days.
