A and B invest ₹ 3000 and ₹ 4000, respectively in a business. A receives ₹ 10 per month out of the profit as a remuneration for running the business and the rest of the profit is divided in proportion to the investments. If in a year A totally receives ₹ 390, what does B receive?

Let the annual profit be ₹ N Then, ₹ (N - 120) will be distributed between A and B as their shares of profit.
Ratio of profits = Ratio of investments So, A : B = 3000 : 4000 = 3 : 4
∴ A's share = 120 + (N - 120) x 3/7
⇒ 120 + (N - 120) x 3/7 = 390
⇒ (N - 120) x 3/7 = 390 - 120 = 270
⇒ N - 120 = (270 x 7)/3 = 630
∵ B's share = 4/7 x (N - 120)
= (4/7) x 630 = ₹ 360