Simple Interest
Math MCQs

Question :    Find the amount to be paid if Richard borrowed a sum of $5600 at 3% simple interest for 7 years.

Correct Answer  $6776

Solution & Explanation

Solution

Given,

Principal (P) = $5600

Rate of Simple Interest (SI) = 3%

Time (t) = 7 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) = $5600 × 3% × 7

= $5600 ׳/₁₀₀ × 7

= ^{5600 × 3 × 7}/₁₀₀

= ^{16800 × 7}/₁₀₀

= ¹¹⁷⁶⁰⁰/₁₀₀

= $1176

Thus, Simple Interest = $1176

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 + $1176

= $6776

Thus, Amount to be paid = $6776 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) = 3%

And, Time (t) = 7 years

Thus, Amount (A)

= $5600 + ($5600 × 3% × 7)

= $5600 + ($5600 ׳/₁₀₀ × 7)

= $5600 + (^{5600 × 3 × 7}/₁₀₀)

= $5600 + (^{16800 × 7}/₁₀₀)

= $5600 + (¹¹⁷⁶⁰⁰/₁₀₀)

= $5600 + $1176 = $6776

Thus, Amount (A) to be paid = $6776 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 $5600, the simple interest in 1 year

= ³/₁₀₀ × 5600

= ^{3 × 5600}/₁₀₀

= ¹⁶⁸⁰⁰/₁₀₀ = $168

Thus, simple interest for 1 year = $168

Therefore, simple interest for 7 years

= Simple interest for 1 year × 7

= $168 × 7 = $1176

Thus, Simple Interest (SI) = $1176

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5600 + $1176

= $6776

Thus, Amount to be paid = $6776 Answer

Similar Questions

(1) Find the amount to be paid if Jessica borrowed a sum of $5750 at 8% simple interest for 8 years.

(2) What amount does Joseph have to pay after 5 years if he takes a loan of $3700 at 8% simple interest?

(3) Sandra took a loan of $6900 at the rate of 10% simple interest per annum. If he paid an amount of $13110 to clear the loan, then find the time period of the loan.

(4) Patricia took a loan of $4300 at the rate of 10% simple interest per annum. If he paid an amount of $8600 to clear the loan, then find the time period of the loan.

(5) Sandra took a loan of $6900 at the rate of 8% simple interest per annum. If he paid an amount of $12420 to clear the loan, then find the time period of the loan.

(6) Thomas took a loan of $5600 at the rate of 10% simple interest per annum. If he paid an amount of $9520 to clear the loan, then find the time period of the loan.

(7) Calculate the amount due after 10 years if Michael borrowed a sum of $5300 at a rate of 4% simple interest.

(8) What amount does Joseph have to pay after 5 years if he takes a loan of $3700 at 3% simple interest?

(9) Calculate the amount due if James borrowed a sum of $3000 at 2% simple interest for 4 years.

(10) What amount does Mary have to pay after 5 years if he takes a loan of $3050 at 3% simple interest?