Question

Find the time (in years) in which Rs. 12500 will produce Rs. 3246.40 as compound interest at 8% per annum , compounded annually

Answer 1

Compound Interest Formula:
$a = p (1 + \frac{r}{n} {)}^{(nt)}$

Given,
p= ₹12,500
a= p+i = ₹(12,500 + 3,246.40) = ₹15,746.49
r= 8% or 0.08 per annum
t= x years

1st year:
S.I:
8% of ₹12,500
=8/100 × 12,500
=8 × 125
=₹1,000
Therefore, 1st year a= ₹(12,500 + 1,000) = ₹13,500

2nd year:
C.I:
8% of ₹13,500
=8/100 × ₹13,500
=8 × 135
=₹1,080
Therefore, 2nd year a= ₹(13,500 + 1,080) = ₹14,580

3rd year:
C.I:
8% of ₹14,580
=8/100 × 14,580
=0.08 × 14,580
= ₹1,166.40
Therefore, 3rd year a= ₹(14,580 + 1,166.40) = ₹ 15,746.40

Total C.I. accumulated in a period of 3 years= ₹ (1,000 + 1,080 + 1,166.40) = ₹3,246.40

Answer- 3 years.

Answer 2

Here is the answer attached