Loan cleared with cash plus asset — price the cow: A farmer borrows ₹ 4200 at 10% per annum simple interest. After 5 years, he pays ₹ 5000 in cash and gives a cow to settle the account fully. What is the cost of the cow?

Introduction / Context:
Simple interest allows direct computation of the total due after a given number of years. If part of the settlement is cash and the rest an asset, the asset’s value is the shortfall to reach the total due.

Given Data / Assumptions:

• Principal P = ₹ 4200
• Rate r = 10% p.a.
• Time t = 5 years
• Cash paid = ₹ 5000; cow value = ?

Concept / Approach:
Total amount due under SI: A = P + (P * r * t) / 100. Then Cow = A − Cash.

Step-by-Step Solution:
Interest I = 4200 * 10 * 5 / 100 = ₹ 2100Total due A = 4200 + 2100 = ₹ 6300Cow value = 6300 − 5000 = ₹ 1300

Verification / Alternative check:
Cash plus cow = 5000 + 1300 = ₹ 6300, equal to total due (correct).

Why Other Options Are Wrong:
₹ 1240, ₹ 1200, ₹ 1340, or ₹ 1100 do not satisfy the exact equality with the computed due amount.

Common Pitfalls:
Mixing SI with compound interest or miscomputing 10% over 5 years (it is 50% of principal).

Final Answer:
₹ 1300