Simple Interest
Math MCQs

Question :    Calculate the amount due after 9 years if John borrowed a sum of $5200 at a rate of 3% simple interest.

Correct Answer  $6604

Solution & Explanation

Solution

Given,

Principal (P) = $5200

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) = $5200 × 3% × 9

= $5200 ׳/₁₀₀ × 9

= ^{5200 × 3 × 9}/₁₀₀

= ^{15600 × 9}/₁₀₀

= ¹⁴⁰⁴⁰⁰/₁₀₀

= $1404

Thus, Simple Interest = $1404

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 = $5200 + $1404

= $6604

Thus, Amount to be paid = $6604 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 = $5200

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

And, Time (t) = 9 years

Thus, Amount (A)

= $5200 + ($5200 × 3% × 9)

= $5200 + ($5200 ׳/₁₀₀ × 9)

= $5200 + (^{5200 × 3 × 9}/₁₀₀)

= $5200 + (^{15600 × 9}/₁₀₀)

= $5200 + (¹⁴⁰⁴⁰⁰/₁₀₀)

= $5200 + $1404 = $6604

Thus, Amount (A) to be paid = $6604 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 $5200, the simple interest in 1 year

= ³/₁₀₀ × 5200

= ^{3 × 5200}/₁₀₀

= ¹⁵⁶⁰⁰/₁₀₀ = $156

Thus, simple interest for 1 year = $156

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $156 × 9 = $1404

Thus, Simple Interest (SI) = $1404

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5200 + $1404

= $6604

Thus, Amount to be paid = $6604 Answer

Similar Questions

(1) Jennifer took a loan of $4500 at the rate of 8% simple interest per annum. If he paid an amount of $6660 to clear the loan, then find the time period of the loan.

(2) Richard took a loan of $5200 at the rate of 8% simple interest per annum. If he paid an amount of $8944 to clear the loan, then find the time period of the loan.

(3) What amount does Patricia have to pay after 5 years if he takes a loan of $3150 at 6% simple interest?

(4) Find the amount to be paid if Barbara borrowed a sum of $5550 at 9% simple interest for 8 years.

(5) If Donna paid $5432 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(6) Calculate the amount due after 10 years if Christopher borrowed a sum of $6000 at a rate of 10% simple interest.

(7) Calculate the amount due if Linda borrowed a sum of $3350 at 9% simple interest for 4 years.

(8) Lisa had to pay $4657.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(9) Calculate the amount due after 10 years if John borrowed a sum of $5200 at a rate of 6% simple interest.

(10) What amount does James have to pay after 6 years if he takes a loan of $3000 at 10% simple interest?