A and B invest Rs.300 and Rs.400 respectively in a business. A reinvests his portion of the first year's profit of Rs.210 back into the business, while B chooses not to reinvest. What is the ratio in which they should share the second year's profit?

Explanation

The initial investments are Rs.300 by A and Rs.400 by B. A's share of the first year's profit (Rs.210) is (300/(300+400)) × 210 = Rs.90, which he reinvests. Therefore, A's total investment for the second year is Rs.300 + Rs.90 = Rs.390, while B's remains Rs.400. The ratio of their investments for the second year is 390:400, which simplifies to 39:40.