Simple Interest
Math MCQs

Question :    Find the amount to be paid if Jennifer borrowed a sum of $5250 at 9% simple interest for 8 years.

Correct Answer  $9030

Solution & Explanation

Solution

Given,

Principal (P) = $5250

Rate of Simple Interest (SI) = 9%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% 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) = $5250 × 9% × 8

= $5250 ×⁹/₁₀₀ × 8

= ^{5250 × 9 × 8}/₁₀₀

= ^{47250 × 8}/₁₀₀

= ³⁷⁸⁰⁰⁰/₁₀₀

= $3780

Thus, Simple Interest = $3780

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 = $5250 + $3780

= $9030

Thus, Amount to be paid = $9030 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 = $5250

Rate of Simple Interest (SI) or (R) = 9%

And, Time (t) = 8 years

Thus, Amount (A)

= $5250 + ($5250 × 9% × 8)

= $5250 + ($5250 ×⁹/₁₀₀ × 8)

= $5250 + (^{5250 × 9 × 8}/₁₀₀)

= $5250 + (^{47250 × 8}/₁₀₀)

= $5250 + (³⁷⁸⁰⁰⁰/₁₀₀)

= $5250 + $3780 = $9030

Thus, Amount (A) to be paid = $9030 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 9%

This, means, $9 per $100 per year

∵ For $100, the simple interest for 1 year = $9

∴ For $1, the simple interest for 1 year = ⁹/₁₀₀

∴ For $5250, the simple interest in 1 year

= ⁹/₁₀₀ × 5250

= ^{9 × 5250}/₁₀₀

= ⁴⁷²⁵⁰/₁₀₀ = $472.5

Thus, simple interest for 1 year = $472.5

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $472.5 × 8 = $3780

Thus, Simple Interest (SI) = $3780

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5250 + $3780

= $9030

Thus, Amount to be paid = $9030 Answer

Similar Questions

(1) Calculate the amount due if Linda borrowed a sum of $3350 at 3% simple interest for 3 years.

(2) Calculate the amount due after 9 years if James borrowed a sum of $5000 at a rate of 9% simple interest.

(3) Susan took a loan of $5300 at the rate of 10% simple interest per annum. If he paid an amount of $9540 to clear the loan, then find the time period of the loan.

(4) How much loan did Timothy borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $9250 to clear it?

(5) In how much time a principal of $3150 will amount to $3622.5 at a simple interest of 3% per annum?

(6) Daniel took a loan of $6200 at the rate of 9% simple interest per annum. If he paid an amount of $10106 to clear the loan, then find the time period of the loan.

(7) Michael had to pay $3696 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(8) Mary had to pay $3233 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(9) Margaret took a loan of $6700 at the rate of 9% simple interest per annum. If he paid an amount of $11524 to clear the loan, then find the time period of the loan.

(10) Calculate the amount due after 10 years if Elizabeth borrowed a sum of $5450 at a rate of 10% simple interest.