Arithmetic

Simple & Compound Interest

Medium

A sum of money becomes ₹5100 after 3 years and ₹5950 after 4 years on compound interest. The rate of interest per annum is:

25/2 %

31/2 %

100/3 %

50/3 %

✅ Correct Option: 4

The difference between the amounts after 4 years and 3 years gives the interest earned in the 4th year:

Interest earned in 4th year $= 5950 - 5100 = 850$ rupees

In compound interest, this interest was earned in 1 year on the amount that existed at the start of that year.

The amount at the start of the 4th year was ₹5100 (the amount after 3 years).

So ₹5100 became ₹5950 in 1 year.

For 1 year, the rate can be calculated as:

Rate $= \dfrac{\text{Interest} \times 100}{\text{Principal} \times \text{Time}}$

Rate $= \dfrac{850 \times 100}{5100 \times 1}$

Rate $= \dfrac{85000}{5100}$

Rate $= \dfrac{850}{51}$

Dividing both numerator and denominator by 17:

$\dfrac{850}{51} = \dfrac{50}{3}$

Therefore, the rate of interest per annum is $\dfrac{50}{3}$ %.

2025: 19 May Shift 2

A sum of money becomes ₹ 20070 after 3 year and ₹ 30105 after 6 years on compound interest. The sum will be

2026: 25 May Shift 2

In how many years Rs. 100000 will become Rs. 1,33,100 at compound interest rate of 10% per annum?

2023: 21 May Shift 1

What sum of money will amount to Rs. 520 in 5 years and to Rs 568 in 7 years on simple interest?

2025: 20 May Shift 1

Consider the compound interest of the following

(A) The compound interest on Rs 16000 at 20% per annum for 9 months, compounded quarterly is: Rs 2522

(B) The compound interest on Rs 2800 at 10% per annum for 18 months, compounded annually is: Rs 434

Choose the correct statement(s):

2024

A certain sum becomes ₹ 2,356 in 3 years and ₹ 2,660 in 5 years on simple interest. The value of sum is:

2025: 20 May Shift 2

Consider the compound interest in the following cases:

(A) The compound interest on Rs 16000 at 20% per annum for 9 months, compounded quarterly is Rs. 2500

(B) The compound interest on Rs 2800 at 10% per annum for 18 months is Rs. 434.

Choose the correct statement(s):

Solution