P invests ₹ 60,000 for 10 months; Q invests ₹ 45,000 for 8 months; and R invests ₹ 75,000 for 6 months in a business. Find the ratio in which the profit should be shared among P, Q, and R, respectively.

Three partners invested in a business in the ratio 8:5:4. They invested their capital for 3 months, 10 months, and 9 months respectively. What was the ratio of their profits?

A started a business with an investment of ₹21,000 and after a few months, B joined him with an investment of ₹15,000. At the end of the year, the total profit was divided between them in the ratio 12 : 5. After how many months did B join the business?