Two digits in John's age are the same as the digit in the Wilson's age, but in reverse order. In 21 years John will be twice as old as Wilson will be then. what is the difference in their current age ?
Choose the correct choice from the following options
A) 25	B) 43	C) 14	D) 36	E) 12

Rationale: john ' s age = 10 x + y so wilson ' s age = 10 y + x . . after 21 years , 10 x + y + 21 = 2 * ( 10 y + x + 21 ) . . . . so 21 + 19 y = 8 x . . . check for odd values of y , y = 1 satisfies the eqn with x = 5 . . . so ages are 51 and 15 and ans as found correctly by u is d . . 36
Answer: D