Simple Interest
Math MCQs

Question :    Calculate the amount due after 9 years if Jennifer borrowed a sum of $5250 at a rate of 2% simple interest.

Correct Answer  $6195

Solution & Explanation

Solution

Given,

Principal (P) = $5250

Rate of Simple Interest (SI) = 2%

Time (t) = 9 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) = $5250 × 2% × 9

= $5250 ײ/₁₀₀ × 9

= ^{5250 × 2 × 9}/₁₀₀

= ^{10500 × 9}/₁₀₀

= ⁹⁴⁵⁰⁰/₁₀₀

= $945

Thus, Simple Interest = $945

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 + $945

= $6195

Thus, Amount to be paid = $6195 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) = 2%

And, Time (t) = 9 years

Thus, Amount (A)

= $5250 + ($5250 × 2% × 9)

= $5250 + ($5250 ײ/₁₀₀ × 9)

= $5250 + (^{5250 × 2 × 9}/₁₀₀)

= $5250 + (^{10500 × 9}/₁₀₀)

= $5250 + (⁹⁴⁵⁰⁰/₁₀₀)

= $5250 + $945 = $6195

Thus, Amount (A) to be paid = $6195 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 $5250, the simple interest in 1 year

= ²/₁₀₀ × 5250

= ^{2 × 5250}/₁₀₀

= ¹⁰⁵⁰⁰/₁₀₀ = $105

Thus, simple interest for 1 year = $105

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $105 × 9 = $945

Thus, Simple Interest (SI) = $945

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5250 + $945

= $6195

Thus, Amount to be paid = $6195 Answer

Similar Questions

(1) How much loan did William borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $6325 to clear it?

(2) How much loan did Daniel borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $6710 to clear it?

(3) Calculate the amount due after 9 years if David borrowed a sum of $5400 at a rate of 3% simple interest.

(4) If David paid $3672 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(5) What amount will be due after 2 years if Thomas borrowed a sum of $3400 at a 9% simple interest?

(6) David took a loan of $4800 at the rate of 7% simple interest per annum. If he paid an amount of $7488 to clear the loan, then find the time period of the loan.

(7) Karen took a loan of $5900 at the rate of 6% simple interest per annum. If he paid an amount of $9086 to clear the loan, then find the time period of the loan.

(8) Find the amount to be paid if William borrowed a sum of $5500 at 6% simple interest for 8 years.

(9) How much loan did Ashley borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $7860 to clear it?

(10) Calculate the amount due after 9 years if Robert borrowed a sum of $5100 at a rate of 5% simple interest.