Sharing based on work rates: A, B and C can finish a job alone in 15, 20 and 25 days respectively. They work together and earn a total of ₹ 4700. What is C's share if the payment is split in proportion to their work rates?

Introduction / Context:
When all three work together for the same time, the payment division should follow their work rates (inverse of the individual times). We compute the fraction of the total work rate contributed by C and allocate ₹ 4700 accordingly.

Given Data / Assumptions:

• A: 1/15, B: 1/20, C: 1/25 job per day
• Total payment = ₹ 4700
• All three work concurrently

Concept / Approach:
C's share fraction = Rate(C) / (Rate(A) + Rate(B) + Rate(C)). Multiply this by the total amount to get C's share in rupees.

Step-by-Step Solution:
Sum of rates = 1/15 + 1/20 + 1/25 = (20 + 15 + 12) / 300 = 47/300C's fraction = (1/25) / (47/300) = (12/300) / (47/300) = 12/47C's share = 12/47 * 4700 = ₹ 1200

Verification / Alternative check:
Note that 47 * 100 = 4700, so 12/47 * 4700 = 12 * 100 = ₹ 1200 directly.

Why Other Options Are Wrong:
₹ 1500, ₹ 1800, ₹ 2000 correspond to larger fractions and do not match the calculated 12/47 of the total.

Common Pitfalls:
Adding times instead of rates; forgetting to normalize by the total of the rates.

Final Answer:
₹ 1200