A sum of money at simple interest amounts to Rs. 815 in 3 years and to Rs. 854 in 4 years. Find the original sum of money. [2 MARKS]
Concept : 1 Mark
Calculation : 1 Mark
S.I. for 1 year = Rs. (854 - 815) = Rs. 39.
S.I. for 3 years =Rs.(39×3)=Rs.117.
Principal = Rs. (815 - 117) = Rs. 698.