Question

at what rate of interest per annum compounded annually in the sum of Rs 1250 amount to Rs 1458 in 2 years​

Answer 1

Answer:

Rate of Interest per annum is 8%

Step-by-step explanation:

C.I. is 1458-1250 = 208

Therefore,

C.I. = P [(1+r/100)^2 - 1]

208 = 1250 [(1+r/100)^2 - 1]

208/1250 = [(100+r/100)^2 - 1] = [(100+r)^2/10000 - 1]

208/1250 + 1250/1250 = (100+r)^2 / 10000

1458×10000/1250 = 10000 +200r + r^2

11664 - 10000 = 200r + r^2

Therefore,

0= r^2+200r+1664

0= r^2 - 8r +208r + 1664

0= r(r+208) -8 (r+208)

0=r-8 OR 0=r+208

r=8 OR r=-208

Rate cannot be negative

Ans. Rate of interest is 8% per annum