A sum of money at simple interest amounts to Rs. 815 in 3 years and to Rs. 874 in 4 years. The sum is:
Options.
A) s. 650 B) s. 638 C) s. 698 D) s. 700 E) s. 760
S.I. for 1 year = Rs. (874 - 815) = Rs. 59.   S.I. for 3 years = Rs.(59 x 3) = Rs. 177.   Principal = Rs. (815 - 177) = Rs. 638.   Answer: Option s. 638
<result>B</result>
A sum of money at simple interest amounts to Rs. 815 in 3 years and to Rs. 874 in 4 years. The sum is: