The compound interest calulated yearly on certain sum of money for the second year is ₹1089and for the third year - Maths - Compound Interest

Question

The compound interest calulated yearly on certain sum of money for
the second year is ₹1089and for the third year it is
₹1197 90 calculate the rate of interest and the sum of
money?(without using formula)

Mayank Gupta · Accepted Answer

Dear student , here is detailed solution to your queryLet ,Principal sum = PRate = r %Now,⇒ C
I  in 1st year = P×r×1100 Therefore amount A1=P+P
r100= P1+r100⇒ C
I  in 2nd year =  A1×r×1100 = P1+r100
r100= 1089
(1)Therefore amount A2= P1+r100 +  P1+r100
r100                          ⇒  A2= P1+r1002⇒C
I  in 3rd year =  A2×r×1100 = P1+r1002
r100 = 1197
(2)    Divide equation (2) by (1) ,⇒1+r100 = 11971089⇒   r = 11971089-1×100 = 1081089×100 = 9
917%Substituting ' r ' in equation (1),⇒ P1+9
917100 9
917100= 1089⇒ P = 1089 ×10010
9 ≈ 9990 826Regards

The compound interest calulated yearly on certain sum of money for the second year is ₹1089and for the third year it is ₹1197.90.calculate the rate of interest and the sum of money?(without using formula)