Simple Interest
Math MCQs

Question :    Find the amount to be paid if Joseph borrowed a sum of $5700 at 7% simple interest for 7 years.

Correct Answer  $8493

Solution & Explanation

Solution

Given,

Principal (P) = $5700

Rate of Simple Interest (SI) = 7%

Time (t) = 7 years

Thus, Amount (A) = ?

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

Thus, here 7% simple interest means, Rate of Simple Interest (SI) is 7% 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) = $5700 × 7% × 7

= $5700 ×⁷/₁₀₀ × 7

= ^{5700 × 7 × 7}/₁₀₀

= ^{39900 × 7}/₁₀₀

= ²⁷⁹³⁰⁰/₁₀₀

= $2793

Thus, Simple Interest = $2793

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 = $5700 + $2793

= $8493

Thus, Amount to be paid = $8493 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 = $5700

Rate of Simple Interest (SI) or (R) = 7%

And, Time (t) = 7 years

Thus, Amount (A)

= $5700 + ($5700 × 7% × 7)

= $5700 + ($5700 ×⁷/₁₀₀ × 7)

= $5700 + (^{5700 × 7 × 7}/₁₀₀)

= $5700 + (^{39900 × 7}/₁₀₀)

= $5700 + (²⁷⁹³⁰⁰/₁₀₀)

= $5700 + $2793 = $8493

Thus, Amount (A) to be paid = $8493 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 7%

This, means, $7 per $100 per year

∵ For $100, the simple interest for 1 year = $7

∴ For $1, the simple interest for 1 year = ⁷/₁₀₀

∴ For $5700, the simple interest in 1 year

= ⁷/₁₀₀ × 5700

= ^{7 × 5700}/₁₀₀

= ³⁹⁹⁰⁰/₁₀₀ = $399

Thus, simple interest for 1 year = $399

Therefore, simple interest for 7 years

= Simple interest for 1 year × 7

= $399 × 7 = $2793

Thus, Simple Interest (SI) = $2793

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5700 + $2793

= $8493

Thus, Amount to be paid = $8493 Answer

Similar Questions

(1) What amount does William have to pay after 6 years if he takes a loan of $3500 at 8% simple interest?

(2) Elizabeth took a loan of $4900 at the rate of 8% simple interest per annum. If he paid an amount of $8036 to clear the loan, then find the time period of the loan.

(3) Calculate the amount due after 10 years if Charles borrowed a sum of $5900 at a rate of 4% simple interest.

(4) Patricia took a loan of $4300 at the rate of 8% simple interest per annum. If he paid an amount of $6364 to clear the loan, then find the time period of the loan.

(5) What amount does Linda have to pay after 6 years if he takes a loan of $3350 at 6% simple interest?

(6) Calculate the amount due if Jessica borrowed a sum of $3750 at 5% simple interest for 4 years.

(7) Find the amount to be paid if William borrowed a sum of $5500 at 3% simple interest for 7 years.

(8) Paul had to pay $4982 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(9) Calculate the amount due if Thomas borrowed a sum of $3800 at 8% simple interest for 4 years.

(10) What amount does Sarah have to pay after 5 years if he takes a loan of $3850 at 9% simple interest?