1.  A sum of money at simple interest amounts to ₹ 815 in 3 years and to ₹ 854 in 4 years. The sum is:
A. ₹ 650
B. ₹ 690
C. ₹ 698
D. ₹ 700

Answer: Option C

Explanation:

S.I. for 1 year = ₹ (854 - 815) = ₹ 39.

S.I. for 3 years = ₹ (39 x 3) = ₹ 117.

∴ Principal = ₹ (815 - 117) = ₹ 698.