Two partners, P and Q, invest in a business with their investment amounts in the ratio 7:5. Their profit shares are in the ratio 7:10. If P's investment duration was 5 months, for how many months did Q invest?

Explanation

Since the profit ratio is determined by the product of investment and time, we have 7 * 5 : 5 * x = 7 : 10. Solving for x gives x = 10 months, which is the duration Q invested.