In 10 years, P will be as old as Q is now. Fifteen years ago, Q was twice as old as P was then. How old is P now?  Pick one:	A) 17	B) 18	C) 21	D) 25	E) 30
Q = P+10   Q-15 = 2(P-15)   P-5 = 2P-30   P = 25   The answer is 25.
<result>D</result>
In 10 years, P will be as old as Q is now. Fifteen years ago, Q was twice as old as P was then. How old is P now?