Correct Answer - Option 3 : Rs. 800
Given:
Time taken by A to do a work = 10 days
Time taken by B to do the same work = 15 days
Time taken by A, B and C do the same work = 5 days
Amount of earning = Rs.4800
Formula used:
Ratio of shares of A, B and C = Ratio of their Efficiency
Calculation:
Let total work be = 1 unit
One day work done by A = 1/10
One day work done by B = 1/15
One day work done by A, B and C = 1/5
⇒ One day work done by C = 1/5 - (1/10 - 1/15)
⇒ 1/30
Ratio of shares of A, B and C = Ratio of their one-day work efficiency
⇒ A : B : C = 1/10 : 1/15 : 1: 30
⇒ A : B : C = 3 : 2 : 1
∴ C's share in earning = Rs.4800 × 1/6
⇒ Rs.800