Simple Interest
Math MCQs

Question :    Calculate the amount due after 9 years if Jennifer borrowed a sum of $5250 at a rate of 8% simple interest.

Correct Answer  $9030

Solution & Explanation

Solution

Given,

Principal (P) = $5250

Rate of Simple Interest (SI) = 8%

Time (t) = 9 years

Thus, Amount (A) = ?

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

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

= $5250 ×⁸/₁₀₀ × 9

= ^{5250 × 8 × 9}/₁₀₀

= ^{42000 × 9}/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) = 8%

And, Time (t) = 9 years

Thus, Amount (A)

= $5250 + ($5250 × 8% × 9)

= $5250 + ($5250 ×⁸/₁₀₀ × 9)

= $5250 + (^{5250 × 8 × 9}/₁₀₀)

= $5250 + (^{42000 × 9}/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 = 8%

This, means, $8 per $100 per year

∵ For $100, the simple interest for 1 year = $8

∴ For $1, the simple interest for 1 year = ⁸/₁₀₀

∴ For $5250, the simple interest in 1 year

= ⁸/₁₀₀ × 5250

= ^{8 × 5250}/₁₀₀

= ⁴²⁰⁰⁰/₁₀₀ = $420

Thus, simple interest for 1 year = $420

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $420 × 9 = $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) Michael took a loan of $4600 at the rate of 9% simple interest per annum. If he paid an amount of $8326 to clear the loan, then find the time period of the loan.

(2) Calculate the amount due if Charles borrowed a sum of $3900 at 3% simple interest for 4 years.

(3) Calculate the amount due if Jennifer borrowed a sum of $3250 at 10% simple interest for 3 years.

(4) If Steven paid $5520 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(5) In how much time a principal of $3000 will amount to $3300 at a simple interest of 2% per annum?

(6) What amount will be due after 2 years if James borrowed a sum of $3000 at a 6% simple interest?

(7) Find the amount to be paid if Linda borrowed a sum of $5350 at 3% simple interest for 8 years.

(8) Michael took a loan of $4600 at the rate of 9% simple interest per annum. If he paid an amount of $7084 to clear the loan, then find the time period of the loan.

(9) Donald took a loan of $7000 at the rate of 9% simple interest per annum. If he paid an amount of $10780 to clear the loan, then find the time period of the loan.

(10) If Sarah borrowed $3850 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.