Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Thomas borrowed a sum of $5800 at a rate of 3% simple interest.

Correct Answer  $7540

Solution & Explanation

Solution

Given,

Principal (P) = $5800

Rate of Simple Interest (SI) = 3%

Time (t) = 10 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) = $5800 × 3% × 10

= $5800 ׳/₁₀₀ × 10

= ^{5800 × 3 × 10}/₁₀₀

= ^{17400 × 10}/₁₀₀

= ¹⁷⁴⁰⁰⁰/₁₀₀

= $1740

Thus, Simple Interest = $1740

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 = $5800 + $1740

= $7540

Thus, Amount to be paid = $7540 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 = $5800

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

And, Time (t) = 10 years

Thus, Amount (A)

= $5800 + ($5800 × 3% × 10)

= $5800 + ($5800 ׳/₁₀₀ × 10)

= $5800 + (^{5800 × 3 × 10}/₁₀₀)

= $5800 + (^{17400 × 10}/₁₀₀)

= $5800 + (¹⁷⁴⁰⁰⁰/₁₀₀)

= $5800 + $1740 = $7540

Thus, Amount (A) to be paid = $7540 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 $5800, the simple interest in 1 year

= ³/₁₀₀ × 5800

= ^{3 × 5800}/₁₀₀

= ¹⁷⁴⁰⁰/₁₀₀ = $174

Thus, simple interest for 1 year = $174

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $174 × 10 = $1740

Thus, Simple Interest (SI) = $1740

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5800 + $1740

= $7540

Thus, Amount to be paid = $7540 Answer

Similar Questions

(1) David took a loan of $4800 at the rate of 9% simple interest per annum. If he paid an amount of $9120 to clear the loan, then find the time period of the loan.

(2) Calculate the amount due if Barbara borrowed a sum of $3550 at 4% simple interest for 4 years.

(3) What amount will be due after 2 years if Christopher borrowed a sum of $3500 at a 7% simple interest?

(4) Linda took a loan of $4700 at the rate of 9% simple interest per annum. If he paid an amount of $8084 to clear the loan, then find the time period of the loan.

(5) Joseph took a loan of $5400 at the rate of 7% simple interest per annum. If he paid an amount of $7668 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due after 10 years if William borrowed a sum of $5500 at a rate of 6% simple interest.

(7) Calculate the amount due if David borrowed a sum of $3400 at 7% simple interest for 4 years.

(8) Michael had to pay $3498 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(9) Richard took a loan of $5200 at the rate of 10% simple interest per annum. If he paid an amount of $9360 to clear the loan, then find the time period of the loan.

(10) Calculate the amount due if Joseph borrowed a sum of $3700 at 7% simple interest for 4 years.