Simple Interest
Math MCQs

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

Correct Answer  $11600

Solution & Explanation

Solution

Given,

Principal (P) = $5800

Rate of Simple Interest (SI) = 10%

Time (t) = 10 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% × 10

= $5800 ×¹⁰/₁₀₀ × 10

= ^{5800 × 10 × 10}/₁₀₀

= ^{58000 × 10}/₁₀₀

= ⁵⁸⁰⁰⁰⁰/₁₀₀

= $5800

Thus, Simple Interest = $5800

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 + $5800

= $11600

Thus, Amount to be paid = $11600 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) = 10 years

Thus, Amount (A)

= $5800 + ($5800 × 10% × 10)

= $5800 + ($5800 ×¹⁰/₁₀₀ × 10)

= $5800 + (^{5800 × 10 × 10}/₁₀₀)

= $5800 + (^{58000 × 10}/₁₀₀)

= $5800 + (⁵⁸⁰⁰⁰⁰/₁₀₀)

= $5800 + $5800 = $11600

Thus, Amount (A) to be paid = $11600 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 10 years

= Simple interest for 1 year × 10

= $580 × 10 = $5800

Thus, Simple Interest (SI) = $5800

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5800 + $5800

= $11600

Thus, Amount to be paid = $11600 Answer

Similar Questions

(1) Calculate the amount due after 9 years if Jennifer borrowed a sum of $5250 at a rate of 5% simple interest.

(2) Find the amount to be paid if Linda borrowed a sum of $5350 at 7% simple interest for 7 years.

(3) Donna had to pay $5141 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(4) How much loan did Thomas borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $6380 to clear it?

(5) Robert took a loan of $4200 at the rate of 9% simple interest per annum. If he paid an amount of $7602 to clear the loan, then find the time period of the loan.

(6) Jessica took a loan of $5500 at the rate of 6% simple interest per annum. If he paid an amount of $7480 to clear the loan, then find the time period of the loan.

(7) Calculate the amount due after 10 years if Thomas borrowed a sum of $5800 at a rate of 4% simple interest.

(8) Emily had to pay $5462.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(9) David took a loan of $4800 at the rate of 7% simple interest per annum. If he paid an amount of $7824 to clear the loan, then find the time period of the loan.

(10) Calculate the amount due if Karen borrowed a sum of $3950 at 7% simple interest for 4 years.