Simple Interest
Math MCQs

Question :    Calculate the amount due after 9 years if Jennifer borrowed a sum of $5250 at a rate of 6% simple interest.

Correct Answer  $8085

Solution & Explanation

Solution

Given,

Principal (P) = $5250

Rate of Simple Interest (SI) = 6%

Time (t) = 9 years

Thus, Amount (A) = ?

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

Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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 × 6% × 9

= $5250 ×⁶/₁₀₀ × 9

= ^{5250 × 6 × 9}/₁₀₀

= ^{31500 × 9}/₁₀₀

= ²⁸³⁵⁰⁰/₁₀₀

= $2835

Thus, Simple Interest = $2835

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 + $2835

= $8085

Thus, Amount to be paid = $8085 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) = 6%

And, Time (t) = 9 years

Thus, Amount (A)

= $5250 + ($5250 × 6% × 9)

= $5250 + ($5250 ×⁶/₁₀₀ × 9)

= $5250 + (^{5250 × 6 × 9}/₁₀₀)

= $5250 + (^{31500 × 9}/₁₀₀)

= $5250 + (²⁸³⁵⁰⁰/₁₀₀)

= $5250 + $2835 = $8085

Thus, Amount (A) to be paid = $8085 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = ⁶/₁₀₀

∴ For $5250, the simple interest in 1 year

= ⁶/₁₀₀ × 5250

= ^{6 × 5250}/₁₀₀

= ³¹⁵⁰⁰/₁₀₀ = $315

Thus, simple interest for 1 year = $315

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $315 × 9 = $2835

Thus, Simple Interest (SI) = $2835

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5250 + $2835

= $8085

Thus, Amount to be paid = $8085 Answer

Similar Questions

(1) Margaret took a loan of $6700 at the rate of 9% simple interest per annum. If he paid an amount of $12127 to clear the loan, then find the time period of the loan.

(2) Calculate the amount due after 9 years if Jessica borrowed a sum of $5750 at a rate of 2% simple interest.

(3) Nancy had to pay $4523.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(4) Jessica took a loan of $5500 at the rate of 7% simple interest per annum. If he paid an amount of $8580 to clear the loan, then find the time period of the loan.

(5) Calculate the amount due after 9 years if Linda borrowed a sum of $5350 at a rate of 4% simple interest.

(6) Calculate the amount due if Charles borrowed a sum of $3900 at 5% simple interest for 4 years.

(7) Charles took a loan of $5800 at the rate of 6% simple interest per annum. If he paid an amount of $7888 to clear the loan, then find the time period of the loan.

(8) Betty had to pay $4505 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(9) How much loan did Joseph borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6840 to clear it?

(10) Calculate the amount due if Mary borrowed a sum of $3050 at 10% simple interest for 3 years.