A sum of money lent out at S.I. amounts to Rs. 820 after 2 years and to Rs. 1020 after a further period of 4 years. The sum is?
Choose the correct choice:
A) s . 440
B) s . 500
C) s . 720
D) s . 740
E) s . 840

Rationale: s . i for 5 years = ( 1020 - 820 ) = rs . 200 . s . i . for 2 years = 200 / 4 * 2 = rs . 100 . principal = ( 820 - 100 ) = rs . 720 . answer : c
Answer: C