Simple Interest
Math MCQs

Question :  ( 1 of 10 )  What amount will be due after 2 years if Robert borrowed a sum of $3050 at a 8% simple interest?

Correct Answer  $3538

Solution & Explanation

Solution

Given,

Principal (P) = $3050

Rate of Simple Interest (SI) = 8%

Time (t) = 2 years

Thus, Amount (A) = ?

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

Thus, here 8% simple interest means, Rate of Simple Interest (SI) is 8% 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) = $3050 × 8% × 2

= $3050 ×⁸/₁₀₀ × 2

= ^{3050 × 8 × 2}/₁₀₀

= ^{24400 × 2}/₁₀₀

= ⁴⁸⁸⁰⁰/₁₀₀

= $488

Thus, Simple Interest = $488

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 = $3050 + $488

= $3538

Thus, Amount to be paid = $3538 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 = $3050

Rate of Simple Interest (SI) or (R) = 8%

And, Time (t) = 2 years

Thus, Amount (A)

= $3050 + ($3050 × 8% × 2)

= $3050 + ($3050 ×⁸/₁₀₀ × 2)

= $3050 + (^{3050 × 8 × 2}/₁₀₀)

= $3050 + (^{24400 × 2}/₁₀₀)

= $3050 + (⁴⁸⁸⁰⁰/₁₀₀)

= $3050 + $488 = $3538

Thus, Amount (A) to be paid = $3538 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 8%

This, means, $8 per $100 per year

∵ For $100, the simple interest for 1 year = $8

∴ For $1, the simple interest for 1 year = ⁸/₁₀₀

∴ For $3050, the simple interest in 1 year

= ⁸/₁₀₀ × 3050

= ^{8 × 3050}/₁₀₀

= ²⁴⁴⁰⁰/₁₀₀ = $244

Thus, simple interest for 1 year = $244

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $244 × 2 = $488

Thus, Simple Interest (SI) = $488

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3050 + $488

= $3538

Thus, Amount to be paid = $3538 Answer

Similar Questions

(1) Find the amount to be paid if Robert borrowed a sum of $5100 at 4% simple interest for 8 years.

(2) Calculate the amount due after 10 years if John borrowed a sum of $5200 at a rate of 10% simple interest.

(3) Calculate the amount due after 10 years if Susan borrowed a sum of $5650 at a rate of 8% simple interest.

(4) Calculate the amount due after 9 years if Charles borrowed a sum of $5900 at a rate of 6% simple interest.

(5) Anthony took a loan of $6600 at the rate of 8% simple interest per annum. If he paid an amount of $10296 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due after 10 years if Elizabeth borrowed a sum of $5450 at a rate of 7% simple interest.

(7) Calculate the amount due after 9 years if Christopher borrowed a sum of $6000 at a rate of 8% simple interest.

(8) Linda took a loan of $4700 at the rate of 8% simple interest per annum. If he paid an amount of $8084 to clear the loan, then find the time period of the loan.

(9) Calculate the amount due if Sarah borrowed a sum of $3850 at 8% simple interest for 4 years.

(10) William had to pay $3920 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.