Question

if the rate of interest be 4% p.a. for first year, 5% p.a. for second year and 6%p.a. for 3rd year, then the compoubd interest of Rs.10000 for 3 years will be:

Answer 1

Let amount be Rs. A.
Principal be Rs P. Here,  P = Rs 10000.
Therefore, A = P(1+4/100)(1+5/100)(1+6/100).
                   = 10,000×(104÷100)×(105÷100)×(106÷100)
                   =  1157520÷100
                   =  11575.20
Required compound interest = Rs ( 11,575.20 - 10,000 ) = Rs 1,575.20. (Ans.)

Answer 2

total amt : $\frac{104}{100} X \frac{105}{100} X \frac{106}{100} X 10,000 \\ =11575.20$

Total interest= 11575.20-10,000= ₹1575.20