In 10 years, P will be as old as Q is now. Ten years ago, Q was three times as old as P was then. How old is P now?
Options:
A) 11
B) 12
C) 15
D) 18
E) 21
Q = P+10   Q-10 = 3(P-10)   P = 3P-30   2P = 30   P = 15   The answer is 15.
<result>C</result>
In 10 years, P will be as old as Q is now. Ten years ago, Q was three times as old as P was then. How old is P now?