Three years ago, the ratio of ages of P and Q was 4:3. Six years from now, the ratio of their ages will be 7:6. What is P's age at present?	Choose the correct choice.
A) 9	B) 12	C) 15	D) 18	E) 21
3(P-3)/4 = (Q-3). Then Q = 3(P-3)/4 + 3   6(P+6)/7 = Q+6   6(P+6)/7 = 3(P-3)/4 + 9   24P+144 = 21P + 189   3P = 45   P = 15   The answer is 15.
<result>C</result>
Three years ago, the ratio of ages of P and Q was 4:3. Six years from now, the ratio of their ages will be 7:6. What is P's age at present?