Simple Interest
Math MCQs

Question :    Calculate the amount due if Michael borrowed a sum of $3300 at 2% simple interest for 4 years.

Correct Answer  $3564

Solution & Explanation

Solution

Given,

Principal (P) = $3300

Rate of Simple Interest (SI) = 2%

Time (t) = 4 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% × 4

= $3300 ײ/₁₀₀ × 4

= ^{3300 × 2 × 4}/₁₀₀

= ^{6600 × 4}/₁₀₀

= ²⁶⁴⁰⁰/₁₀₀

= $264

Thus, Simple Interest = $264

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 + $264

= $3564

Thus, Amount to be paid = $3564 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) = 4 years

Thus, Amount (A)

= $3300 + ($3300 × 2% × 4)

= $3300 + ($3300 ײ/₁₀₀ × 4)

= $3300 + (^{3300 × 2 × 4}/₁₀₀)

= $3300 + (^{6600 × 4}/₁₀₀)

= $3300 + (²⁶⁴⁰⁰/₁₀₀)

= $3300 + $264 = $3564

Thus, Amount (A) to be paid = $3564 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 4 years

= Simple interest for 1 year × 4

= $66 × 4 = $264

Thus, Simple Interest (SI) = $264

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3300 + $264

= $3564

Thus, Amount to be paid = $3564 Answer

Similar Questions

(1) David took a loan of $4800 at the rate of 10% simple interest per annum. If he paid an amount of $7680 to clear the loan, then find the time period of the loan.

(2) Calculate the amount due after 9 years if Joseph borrowed a sum of $5700 at a rate of 6% simple interest.

(3) Find the amount to be paid if Patricia borrowed a sum of $5150 at 4% simple interest for 7 years.

(4) Calculate the amount due if David borrowed a sum of $3400 at 8% simple interest for 4 years.

(5) Mary took a loan of $4100 at the rate of 9% simple interest per annum. If he paid an amount of $6314 to clear the loan, then find the time period of the loan.

(6) Find the amount to be paid if Susan borrowed a sum of $5650 at 2% simple interest for 8 years.

(7) Susan took a loan of $5300 at the rate of 9% simple interest per annum. If he paid an amount of $9593 to clear the loan, then find the time period of the loan.

(8) William had to pay $3920 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(9) Calculate the amount due if Richard borrowed a sum of $3600 at 10% simple interest for 3 years.

(10) Calculate the amount due if Barbara borrowed a sum of $3550 at 9% simple interest for 3 years.