Simple Interest
Math MCQs

Question :    Calculate the amount due after 9 years if Karen borrowed a sum of $5950 at a rate of 2% simple interest.

Correct Answer  $7021

Solution & Explanation

Solution

Given,

Principal (P) = $5950

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) = $5950 × 2% × 9

= $5950 ײ/₁₀₀ × 9

= ^{5950 × 2 × 9}/₁₀₀

= ^{11900 × 9}/₁₀₀

= ¹⁰⁷¹⁰⁰/₁₀₀

= $1071

Thus, Simple Interest = $1071

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 = $5950 + $1071

= $7021

Thus, Amount to be paid = $7021 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 = $5950

Rate of Simple Interest (SI) or (R) = 2%

And, Time (t) = 9 years

Thus, Amount (A)

= $5950 + ($5950 × 2% × 9)

= $5950 + ($5950 ײ/₁₀₀ × 9)

= $5950 + (^{5950 × 2 × 9}/₁₀₀)

= $5950 + (^{11900 × 9}/₁₀₀)

= $5950 + (¹⁰⁷¹⁰⁰/₁₀₀)

= $5950 + $1071 = $7021

Thus, Amount (A) to be paid = $7021 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 $5950, the simple interest in 1 year

= ²/₁₀₀ × 5950

= ^{2 × 5950}/₁₀₀

= ¹¹⁹⁰⁰/₁₀₀ = $119

Thus, simple interest for 1 year = $119

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $119 × 9 = $1071

Thus, Simple Interest (SI) = $1071

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5950 + $1071

= $7021

Thus, Amount to be paid = $7021 Answer

Similar Questions

(1) Calculate the amount due if Richard borrowed a sum of $3600 at 4% simple interest for 4 years.

(2) What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 10% simple interest?

(3) How much loan did Thomas borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $7250 to clear it?

(4) What amount will be due after 2 years if Andrew borrowed a sum of $3900 at a 5% simple interest?

(5) What amount does Michael have to pay after 6 years if he takes a loan of $3300 at 9% simple interest?

(6) Anthony took a loan of $6600 at the rate of 7% simple interest per annum. If he paid an amount of $10758 to clear the loan, then find the time period of the loan.

(7) What amount does Richard have to pay after 6 years if he takes a loan of $3600 at 2% simple interest?

(8) What amount does Joseph have to pay after 5 years if he takes a loan of $3700 at 10% simple interest?

(9) Find the amount to be paid if Charles borrowed a sum of $5900 at 8% simple interest for 7 years.

(10) Calculate the amount due if Jessica borrowed a sum of $3750 at 5% simple interest for 3 years.