Question

A and B undertake a piece of work for Rs. 300. A can do it in 20 days and B can do it in 60 days. With the help of C, they finish it in 10 days. How much should C be paid for her contribution?
1. Rs. 100
2. Rs. 200
3. Rs. 300
4. Rs. 250
5. Rs. 150

Answer 1

Correct Answer - Option 1 : Rs. 100

Given:

A and B undertake a piece of work for Rs. 300

A can do it in 20 days

B can do it in 60 days

Calculation:

A’s efficiency = 60/20 = 3 

B’s efficiency = 60/60 = 1 

Combined Efficiency of A, B, and C = 60/10= 6 

C’s efficiency = 6 – 3 -1 = 2 

C contributed 1/3 of the total work done.

∴ C should be paid 1/3 of the total amount = 300/3 = Rs. 100