Simple Interest – Aptitude Questions and Answers

Simple Interest is an important topic in Quantitative Aptitude, which involves calculating the interest earned or paid on a principal amount over a specified period of time. This chapter is an essential part of many competitive exams, such as SSC and Bank exams, and can be challenging for some candidates.

Prerequisites:

• Simple Interest
• Shortcuts and Tricks for Simple Interest

Aptitude Questions on Simple Interest 

Q1: What would be the annual interest accrued on a deposit of Rs. 10,000 in a bank that pays a 4 % per annum rate of simple interest?

Solution : 

Here, P = 10000, R = 4, T = 1
=> SI = P x R x T / 100
=> SI = 10000 x 4 x 1 / 100
=> SI = 400
Thus, the annual interest would be Rs. 400

Q2: A sum of money amounts to Rs. 28,000 in 2 years at 20 % simple interest per annum. Find the sum.

Solution : 

Here, A = 28000, T = 2, R = 20
=> A = P + SI
=> A = P + (P x R x T / 100)
=> A = P [1 + (R x T / 100)]
=> 28000 = P [1 + 0.4]
=> P = 28000 / 1.4
=> P = 20000
Thus, the required sum is Rs. 20,000

Q3: A man borrowed a certain sum of money at the rate of 6 % per annum for the first two years, 9% per annum for the next three years, and 14% per annum for the period beyond 5 years. If he pays a total interest of Rs. 22,800 at the end of 9 years, find the amount he borrowed.

Solution: 

Let the borrowed sum be P.
=> SI for first 2 years + SI for next 3 years + SI for next 4 years = 22800
=> (P x 6 x 2 / 100) + (P x 9 x 3 / 100) + (P x 14 x 4 / 100) = 22800
=> 95 P / 100 = 22800
=> P = 24000
Therefore, Borrowed sum = Rs. 24,000

Q4: At what annual rate of interest will a sum of money be thrice in 10 years?

Solution : 

Amount = Principal + SI
If the sum of money would be thrice the principal after 10 years, the SI would be twice the principal.
=> SI = 2 x P
=> (P x R x T / 100) = 2 X P
=> R x T / 100 = 2
=> R x T = 200
=> R x 10 = 200
=> R = 20 %
Thus, the required rate of interest is 20 %

Q5: The simple interest on a sum of money in 5 years at 12 % per annum is Rs. 400 less than the simple interest accrued on the same sum in 7 years at 10 % per annum. Find the sum.

Solution: 

Let the sum be P.
=> SI in 5 years at 12 % per annum = P x 12 x 5 / 100 = 0.6 P
=> SI in 7 years at 10 % per annum = P x 10 x 7 / 100 = 0.7 P
Now, according to the question,
0.7 P – 0.6 P = 400
=> 0.1 P = 400
=> P = 4000
Thus, the required sum is Rs. 4000

Q6: A sum of Rs. 1000 was lent to two people, one at the rate of 5 % and the other at the rate of 8 %. If the simple interest after one year is Rs. 62, find the sum lent at each rate.

Solution: 

Let the sum lent at 5 % be P.
=> Sum lent at 8 % = 1000 – P
Now, according to the question,
SI for 5 % + SI for 8 % = 62
=> (P x 5 x 1 / 100) + ((1000 – P) x 8 x 1 / 100) =62
=> 5 P + 8 (1000 – P) = 6200
=> 5 P + 8000 – 8 P = 6200
=> 3 P = 1800
=> P = 600
Therefore, sum lent at 5 % = P = Rs. 600
Sum lent at 8 % = 1000 – P = Rs. 400

Q7: Calculate the simple interest on a loan of $2,000 taken for 2 years at an interest rate of 6% per year.

Solution:

SI = P × R × T/ 100​

Substituting the given values:

P = $2,000
R = 6% per year
T = 2 years

SI = 2000 × 6 × 2 / 100 = $240.

Q8: John takes out a personal loan from his local bank for $15,000 to remodel his kitchen. The bank offers him a simple interest rate of 4.5% per year. If John plans to repay the loan in 5 years, how much will he pay in interest by the end of the loan period?

To find the simple interest, we use the formula:

SI = P × R × T / 100​

P = $15,000
R = 4.5%
T = 5 years

SI = 15000 × 4.5 × 5 / 100

So, by the end of the 5 years, John will pay $3,375 in interest on the $15,000 loan.

Practice Problems on Simple Interest

1. Calculate the simple interest on a loan of $4,500 at a rate of 3% per annum for 3 years.

2. Find the total amount payable at the end of the loan period if $2,000 is borrowed at an interest rate of 5.5% per annum for 5 years.

3. How much interest will an investment of $10,000 earn at an annual interest rate of 6% after 4 years?

4. A sum of $8,000 is invested at a simple interest rate of 7% per annum. Find the simple interest earned after 6 months.

5. If $3,500 is lent for 7 years at a simple interest rate of 8%, what will be the total amount due at the end of the loan term?

6. Determine the principal amount that, when invested at a simple interest rate of 4% per year for 3 years, will generate $600 in interest.

7. Calculate how long it will take for an investment of $5,000 to earn $650 in interest at a simple interest rate of 5% per annum.

8. At what annual interest rate must $1,500 be invested to earn $450 in simple interest over 5 years?

Related Articles:

• Problems on Simple Interest
• Advance Level of Simple Interest

Practice Quiz: Practice Simple Interest Aptitude Quiz Questions

Also Practice:

• Averages Aptitude Questions
• Allegations and Mixtures Aptitude Questions
• Ratio and Proportions Aptitude Questions 
• Compound Interest Aptitude Questions
• Percentages Aptitude Questions
• Profit & Loss Aptitude Questions

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