Simple Interest
Math MCQs

Question :    Calculate the amount due after 9 years if Richard borrowed a sum of $5600 at a rate of 2% simple interest.

Correct Answer  $6608

Solution & Explanation

Solution

Given,

Principal (P) = $5600

Rate of Simple Interest (SI) = 2%

Time (t) = 9 years

Thus, Amount (A) = ?

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

Thus, here 2% simple interest means, Rate of Simple Interest (SI) is 2% 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) = $5600 × 2% × 9

= $5600 ײ/₁₀₀ × 9

= ^{5600 × 2 × 9}/₁₀₀

= ^{11200 × 9}/₁₀₀

= ¹⁰⁰⁸⁰⁰/₁₀₀

= $1008

Thus, Simple Interest = $1008

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 = $5600 + $1008

= $6608

Thus, Amount to be paid = $6608 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 = $5600

Rate of Simple Interest (SI) or (R) = 2%

And, Time (t) = 9 years

Thus, Amount (A)

= $5600 + ($5600 × 2% × 9)

= $5600 + ($5600 ײ/₁₀₀ × 9)

= $5600 + (^{5600 × 2 × 9}/₁₀₀)

= $5600 + (^{11200 × 9}/₁₀₀)

= $5600 + (¹⁰⁰⁸⁰⁰/₁₀₀)

= $5600 + $1008 = $6608

Thus, Amount (A) to be paid = $6608 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 2%

This, means, $2 per $100 per year

∵ For $100, the simple interest for 1 year = $2

∴ For $1, the simple interest for 1 year = ²/₁₀₀

∴ For $5600, the simple interest in 1 year

= ²/₁₀₀ × 5600

= ^{2 × 5600}/₁₀₀

= ¹¹²⁰⁰/₁₀₀ = $112

Thus, simple interest for 1 year = $112

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $112 × 9 = $1008

Thus, Simple Interest (SI) = $1008

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5600 + $1008

= $6608

Thus, Amount to be paid = $6608 Answer

Similar Questions

(1) Calculate the amount due after 9 years if Michael borrowed a sum of $5300 at a rate of 9% simple interest.

(2) Jessica took a loan of $5500 at the rate of 6% simple interest per annum. If he paid an amount of $7810 to clear the loan, then find the time period of the loan.

(3) Jessica took a loan of $5500 at the rate of 9% simple interest per annum. If he paid an amount of $8470 to clear the loan, then find the time period of the loan.

(4) Calculate the amount due if John borrowed a sum of $3200 at 10% simple interest for 4 years.

(5) Calculate the amount due if James borrowed a sum of $3000 at 7% simple interest for 3 years.

(6) Mary took a loan of $4100 at the rate of 7% simple interest per annum. If he paid an amount of $5822 to clear the loan, then find the time period of the loan.

(7) Calculate the amount due if Charles borrowed a sum of $3900 at 9% simple interest for 3 years.

(8) Find the amount to be paid if David borrowed a sum of $5400 at 5% simple interest for 8 years.

(9) Find the amount to be paid if Joseph borrowed a sum of $5700 at 6% simple interest for 7 years.

(10) Kenneth had to pay $5300 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.