The ratio of investments of two partners P and Q is 7:5 and the ratio of their profits is 7:10. If P invested the money for 10 months, find for how much time did Q invest the money?	Choose the correct choice from the following
A) 11
B) 10
C) 20
D) 16
E) 12

Rationale: "7 * 5 : 10 * x = 7 : 10 x = 20 answer : c"
Answer: C