Simple Interest
Math MCQs

Question :    Find the amount to be paid if Susan borrowed a sum of $5650 at 2% simple interest for 7 years.

Correct Answer  $6441

Solution & Explanation

Solution

Given,

Principal (P) = $5650

Rate of Simple Interest (SI) = 2%

Time (t) = 7 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) = $5650 × 2% × 7

= $5650 ײ/₁₀₀ × 7

= ^{5650 × 2 × 7}/₁₀₀

= ^{11300 × 7}/₁₀₀

= ⁷⁹¹⁰⁰/₁₀₀

= $791

Thus, Simple Interest = $791

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 = $5650 + $791

= $6441

Thus, Amount to be paid = $6441 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 = $5650

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

And, Time (t) = 7 years

Thus, Amount (A)

= $5650 + ($5650 × 2% × 7)

= $5650 + ($5650 ײ/₁₀₀ × 7)

= $5650 + (^{5650 × 2 × 7}/₁₀₀)

= $5650 + (^{11300 × 7}/₁₀₀)

= $5650 + (⁷⁹¹⁰⁰/₁₀₀)

= $5650 + $791 = $6441

Thus, Amount (A) to be paid = $6441 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 $5650, the simple interest in 1 year

= ²/₁₀₀ × 5650

= ^{2 × 5650}/₁₀₀

= ¹¹³⁰⁰/₁₀₀ = $113

Thus, simple interest for 1 year = $113

Therefore, simple interest for 7 years

= Simple interest for 1 year × 7

= $113 × 7 = $791

Thus, Simple Interest (SI) = $791

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5650 + $791

= $6441

Thus, Amount to be paid = $6441 Answer

Similar Questions

(1) Find the amount to be paid if Michael borrowed a sum of $5300 at 5% simple interest for 7 years.

(2) Richard took a loan of $5200 at the rate of 9% simple interest per annum. If he paid an amount of $8008 to clear the loan, then find the time period of the loan.

(3) Patricia took a loan of $4300 at the rate of 8% simple interest per annum. If he paid an amount of $7052 to clear the loan, then find the time period of the loan.

(4) Barbara took a loan of $5100 at the rate of 9% simple interest per annum. If he paid an amount of $7854 to clear the loan, then find the time period of the loan.

(5) Find the amount to be paid if Barbara borrowed a sum of $5550 at 8% simple interest for 8 years.

(6) What amount does Barbara have to pay after 5 years if he takes a loan of $3550 at 10% simple interest?

(7) William took a loan of $5000 at the rate of 9% simple interest per annum. If he paid an amount of $7700 to clear the loan, then find the time period of the loan.

(8) Calculate the amount due if Joseph borrowed a sum of $3700 at 9% simple interest for 3 years.

(9) Elizabeth took a loan of $4900 at the rate of 9% simple interest per annum. If he paid an amount of $7546 to clear the loan, then find the time period of the loan.

(10) How much loan did Timothy borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $9250 to clear it?