A father said his son , " I was as old as you are at present at the time of your birth. " If the father age is 48 now, the son age 5 years back was Choose the correct choice from the following:
A) 14
B) 17
C) 11
D) 19
E) 99

Rationale: "let the son ' s present age be x years . then , ( 48 - x ) = x x = 24 . son ' s age 5 years back = ( 24 - 5 ) = 19 years answer : d"
Answer: D