a) ₹650

b) ₹700

c) ₹750

d) ₹800

correct answer is: c) ₹750

Explanation

To find the principal amount (sum) that would yield a simple interest of ₹660 in 11 years at an annual interest rate of 8%, we can use the formula for simple interest = \frac{p\ \times\ r\ \times\ t}{100}
Here,
S.I. = ₹ 660
Time (t) = 11 years
Rate (r) = 8 % p.a.
We know, S.I. = \frac{p\ \times\ r\ \times\ t}{100}
Or, P =\frac{S.I.\ \ \times\ 100}{r\ \times\ t} _{[interchange]}
Putting the value, we get:
P =₹\frac{660\times100}{8\times11}
\rightarrow P = ₹ 750
So, the principal amount is ₹ 750 .
Ans: A sum of ₹750 would yield a simple interest of ₹660 in 11 years at a rate of 8% per annum.

Other ways to ask this same question are:
1. Calculate the principal amount required to generate a simple interest of ₹660 over a period of 11 years at an annual interest rate of 8%.
2. Find out the initial investment needed to earn a simple interest of ₹660 in 11 years at a 8% per annum interest rate.
3. What is the principal amount required to accrue a simple interest of ₹660 over 11 years at a rate of 8% per annum?
4. Determine the principal sum that would yield a simple interest of ₹660 over an 11 year period at an interest rate of 8% per annum.
5. Calculate the sum of money needed to produce a simple interest of ₹660 over an 11 year period with an annual interest rate of 8%.