Question

A sum of Rs 31,250 amounts to Rs 35,152 in 1 1/2 years. Find the rate per annum, interest being compounded semi-annually.

Answer 1

the interest = amount minus sum
that is Rs.35152 minus Rs. 31250
= Rs.3902

the rate per annum = simple interest x 100 / sum x time
= 3902x100 / 31250x (11/2)
= 5.6% (approximately)
hope my answer is correct !!!

Answer 2

Answer: The rate per annum semi compounded is 8%.

Step-by-step explanation:

Since we have given that

Amount = Rs. 35,152

Principal = Rs. 31,250

Number of years = $1\dfrac{1}{2}=\dfrac{3}{2}$ years

We need to find the rate of interest , when interest being compounded semi annually.

so, it becomes

$35152=31250(1+\dfrac{r}{200})^{2n}\\\\\dfrac{35152}{31250}=(1+\dfrac{r}{200})^3\\\\1.124=(1+\dfrac{r}{200})^3\\\\\sqrt[3]{1.124}=(1+\dfrac{r}{200})^3\\\\1.04=1+\dfrac{r}{200}\\\\1.04-1=\dfrac{r}{200}\\\\0.04\times 200=r\\\\8\%=r$

Hence, the rate per annum semi compounded is 8%.