Simple Interest
Math MCQs

Question :    Calculate the amount due if Michael borrowed a sum of $3300 at 2% simple interest for 3 years.

Correct Answer  $3498

Solution & Explanation

Solution

Given,

Principal (P) = $3300

Rate of Simple Interest (SI) = 2%

Time (t) = 3 years

Thus, Amount (A) = ?

The Rate of Interest is always calculated per annum, i.e. per year.

Thus, here 2% simple interest means, Rate of Simple Interest (SI) is 2% per annum.

Method (1) Using Formula

Calculation of Simple Interest

Formula to Calculate Simple Interest

Simple Interest (SI) = Principal × Rate × Time

Thus, Simple Interest (SI) = $3300 × 2% × 3

= $3300 ײ/₁₀₀ × 3

= ^{3300 × 2 × 3}/₁₀₀

= ^{6600 × 3}/₁₀₀

= ¹⁹⁸⁰⁰/₁₀₀

= $198

Thus, Simple Interest = $198

Calculation of Amount

The total money paid to the lender by a borrower is called the Amount.

In other words, sum of priciple and interest is called the Amount.

Formula to Calculate the Amount

Amount = Principal + Interest

Thus, Amount = $3300 + $198

= $3498

Thus, Amount to be paid = $3498 Answer

Method (2)

Calculation of Amount when Principal, Rate of Simple Interest and Time are given

Calculation of Amount directly using Principal, SI, and Time

Formula to calculate the Amount

Amount (A) = Principal (P) + Principal(P) × Rate of Interest (SI) × Time (t)

⇒ A = P + PRT

Here in the question, P = $3300

Rate of Simple Interest (SI) or (R) = 2%

And, Time (t) = 3 years

Thus, Amount (A)

= $3300 + ($3300 × 2% × 3)

= $3300 + ($3300 ײ/₁₀₀ × 3)

= $3300 + (^{3300 × 2 × 3}/₁₀₀)

= $3300 + (^{6600 × 3}/₁₀₀)

= $3300 + (¹⁹⁸⁰⁰/₁₀₀)

= $3300 + $198 = $3498

Thus, Amount (A) to be paid = $3498 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 2%

This, means, $2 per $100 per year

∵ For $100, the simple interest for 1 year = $2

∴ For $1, the simple interest for 1 year = ²/₁₀₀

∴ For $3300, the simple interest in 1 year

= ²/₁₀₀ × 3300

= ^{2 × 3300}/₁₀₀

= ⁶⁶⁰⁰/₁₀₀ = $66

Thus, simple interest for 1 year = $66

Therefore, simple interest for 3 years

= Simple interest for 1 year × 3

= $66 × 3 = $198

Thus, Simple Interest (SI) = $198

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3300 + $198

= $3498

Thus, Amount to be paid = $3498 Answer

Similar Questions

(1) Calculate the amount due after 10 years if William borrowed a sum of $5500 at a rate of 2% simple interest.

(2) Calculate the amount due if Karen borrowed a sum of $3950 at 3% simple interest for 4 years.

(3) Calculate the amount due if Michael borrowed a sum of $3300 at 8% simple interest for 4 years.

(4) Thomas had to pay $4028 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(5) What amount does Joseph have to pay after 6 years if he takes a loan of $3700 at 7% simple interest?

(6) In how much time a principal of $3200 will amount to $3328 at a simple interest of 2% per annum?

(7) Calculate the amount due after 9 years if Sarah borrowed a sum of $5850 at a rate of 2% simple interest.

(8) Daniel took a loan of $6200 at the rate of 6% simple interest per annum. If he paid an amount of $9548 to clear the loan, then find the time period of the loan.

(9) Linda took a loan of $4700 at the rate of 10% simple interest per annum. If he paid an amount of $8930 to clear the loan, then find the time period of the loan.

(10) Calculate the amount due after 10 years if Joseph borrowed a sum of $5700 at a rate of 9% simple interest.