John was thrice as old as Tom 6 years ago. John will be 15/13 times as old as Tom in 6 years. How old is Tom today?  Choose the correct choice from the following options:
A) 5  B) 7  C) 9  D) 11  E) 13
J-6 = 3(T-6), so J = 3T-12   J+6 = 15/13 * (T+6)   13J + 78 = 15T + 90   13(3T-12) + 78 = 15T + 90   24T = 168   T = 7   The answer is 7.
<result>B</result>
John was thrice as old as Tom 6 years ago. John will be 15/13 times as old as Tom in 6 years. How old is Tom today?