A and B invest Rs. 20,000 and Rs. 15,000 respectively. After 6 months, C joins with Rs. 20,000. If the total profit at the end of 2 years from start is Rs. 25,000, what is B's share?

Problem restatement
Compute profit shares via capital × time. A and B invest from the start; C enters after 6 months. The business runs for 24 months from the start.

Given data

• A = 20,000 for 24 months ⇒ 480,000 units
• B = 15,000 for 24 months ⇒ 360,000 units
• C = 20,000 for 18 months ⇒ 360,000 units
• Total profit = Rs. 25,000

Concept/Approach
Profit share = (partner's units) ÷ (total units) × total profit.

Step-by-step calculation
Total units = 480,000 + 360,000 + 360,000 = 1,200,000B's fraction = 360,000 ÷ 1,200,000 = 0.30B's profit = 0.30 × 25,000 = Rs. 7,500

Verification/Alternative
Shares are proportional: A : B : C = 480 : 360 : 360 = 4 : 3 : 3; total parts = 10; B gets 3⁄10 of 25,000 = 7,500.

Common pitfalls
Using 24 months for C as well (C joined after 6 months; only 18 months counted).

Final Answer
Rs. 7,500