Simple Interest
Math MCQs

Question :    Calculate the amount due after 9 years if Thomas borrowed a sum of $5800 at a rate of 10% simple interest.

Correct Answer  $11020

Solution & Explanation

Solution

Given,

Principal (P) = $5800

Rate of Simple Interest (SI) = 10%

Time (t) = 9 years

Thus, Amount (A) = ?

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

Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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 × 10% × 9

= $5800 ×¹⁰/₁₀₀ × 9

= ^{5800 × 10 × 9}/₁₀₀

= ^{58000 × 9}/₁₀₀

= ⁵²²⁰⁰⁰/₁₀₀

= $5220

Thus, Simple Interest = $5220

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 + $5220

= $11020

Thus, Amount to be paid = $11020 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) = 10%

And, Time (t) = 9 years

Thus, Amount (A)

= $5800 + ($5800 × 10% × 9)

= $5800 + ($5800 ×¹⁰/₁₀₀ × 9)

= $5800 + (^{5800 × 10 × 9}/₁₀₀)

= $5800 + (^{58000 × 9}/₁₀₀)

= $5800 + (⁵²²⁰⁰⁰/₁₀₀)

= $5800 + $5220 = $11020

Thus, Amount (A) to be paid = $11020 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 10%

This, means, $10 per $100 per year

∵ For $100, the simple interest for 1 year = $10

∴ For $1, the simple interest for 1 year = ¹⁰/₁₀₀

∴ For $5800, the simple interest in 1 year

= ¹⁰/₁₀₀ × 5800

= ^{10 × 5800}/₁₀₀

= ⁵⁸⁰⁰⁰/₁₀₀ = $580

Thus, simple interest for 1 year = $580

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $580 × 9 = $5220

Thus, Simple Interest (SI) = $5220

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5800 + $5220

= $11020

Thus, Amount to be paid = $11020 Answer

Similar Questions

(1) Daniel took a loan of $6200 at the rate of 7% simple interest per annum. If he paid an amount of $10106 to clear the loan, then find the time period of the loan.

(2) Calculate the amount due if Thomas borrowed a sum of $3800 at 8% simple interest for 3 years.

(3) What amount does Elizabeth have to pay after 5 years if he takes a loan of $3450 at 10% simple interest?

(4) Sandra took a loan of $6900 at the rate of 8% simple interest per annum. If he paid an amount of $11316 to clear the loan, then find the time period of the loan.

(5) Michael had to pay $3597 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(6) Karen took a loan of $5900 at the rate of 8% simple interest per annum. If he paid an amount of $9204 to clear the loan, then find the time period of the loan.

(7) What amount will be due after 2 years if Michael borrowed a sum of $3150 at a 10% simple interest?

(8) Calculate the amount due after 10 years if Linda borrowed a sum of $5350 at a rate of 8% simple interest.

(9) In how much time a principal of $3200 will amount to $3584 at a simple interest of 4% per annum?

(10) What amount will be due after 2 years if Donald borrowed a sum of $3750 at a 9% simple interest?