The bankers discount of a certain sum of money is Rs. 144 and the true discount on the same sum for the same time is Rs. 120. The sum due is:	Choose the correct choice from the following:
A) 715 B) 716 C) 718 D) 720 E) 722

Rationale: sum = ( b . d * t . d ) / ( b . d - t . d ) ( 144 * 120 ) / 144 - 120 ; 720 answer : d
Answer: D