Simple Interest
Math MCQs

Question :    Calculate the amount due after 9 years if Charles borrowed a sum of $5900 at a rate of 3% simple interest.

Correct Answer  $7493

Solution & Explanation

Solution

Given,

Principal (P) = $5900

Rate of Simple Interest (SI) = 3%

Time (t) = 9 years

Thus, Amount (A) = ?

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

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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) = $5900 × 3% × 9

= $5900 ׳/₁₀₀ × 9

= ^{5900 × 3 × 9}/₁₀₀

= ^{17700 × 9}/₁₀₀

= ¹⁵⁹³⁰⁰/₁₀₀

= $1593

Thus, Simple Interest = $1593

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 = $5900 + $1593

= $7493

Thus, Amount to be paid = $7493 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 = $5900

Rate of Simple Interest (SI) or (R) = 3%

And, Time (t) = 9 years

Thus, Amount (A)

= $5900 + ($5900 × 3% × 9)

= $5900 + ($5900 ׳/₁₀₀ × 9)

= $5900 + (^{5900 × 3 × 9}/₁₀₀)

= $5900 + (^{17700 × 9}/₁₀₀)

= $5900 + (¹⁵⁹³⁰⁰/₁₀₀)

= $5900 + $1593 = $7493

Thus, Amount (A) to be paid = $7493 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = ³/₁₀₀

∴ For $5900, the simple interest in 1 year

= ³/₁₀₀ × 5900

= ^{3 × 5900}/₁₀₀

= ¹⁷⁷⁰⁰/₁₀₀ = $177

Thus, simple interest for 1 year = $177

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $177 × 9 = $1593

Thus, Simple Interest (SI) = $1593

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5900 + $1593

= $7493

Thus, Amount to be paid = $7493 Answer

Similar Questions

(1) If Emily paid $5130 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(2) Robert had to pay $3565 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(3) Mark took a loan of $6800 at the rate of 7% simple interest per annum. If he paid an amount of $10132 to clear the loan, then find the time period of the loan.

(4) Karen took a loan of $5900 at the rate of 9% simple interest per annum. If he paid an amount of $9086 to clear the loan, then find the time period of the loan.

(5) Calculate the amount due if David borrowed a sum of $3400 at 10% simple interest for 3 years.

(6) What amount does Christopher have to pay after 6 years if he takes a loan of $4000 at 5% simple interest?

(7) Calculate the amount due if Charles borrowed a sum of $3900 at 8% simple interest for 3 years.

(8) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 2% simple interest for 7 years.

(9) Calculate the amount due after 10 years if Susan borrowed a sum of $5650 at a rate of 4% simple interest.

(10) What amount does David have to pay after 5 years if he takes a loan of $3400 at 7% simple interest?