Simple Interest
Math MCQs

Question :    What amount will be due after 2 years if Steven borrowed a sum of $3800 at a 8% simple interest?

Correct Answer  $4408

Solution & Explanation

Solution

Given,

Principal (P) = $3800

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) = $3800 × 8% × 2

= $3800 ×⁸/₁₀₀ × 2

= ^{3800 × 8 × 2}/₁₀₀

= ^{30400 × 2}/₁₀₀

= ⁶⁰⁸⁰⁰/₁₀₀

= $608

Thus, Simple Interest = $608

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 = $3800 + $608

= $4408

Thus, Amount to be paid = $4408 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 = $3800

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

And, Time (t) = 2 years

Thus, Amount (A)

= $3800 + ($3800 × 8% × 2)

= $3800 + ($3800 ×⁸/₁₀₀ × 2)

= $3800 + (^{3800 × 8 × 2}/₁₀₀)

= $3800 + (^{30400 × 2}/₁₀₀)

= $3800 + (⁶⁰⁸⁰⁰/₁₀₀)

= $3800 + $608 = $4408

Thus, Amount (A) to be paid = $4408 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 $3800, the simple interest in 1 year

= ⁸/₁₀₀ × 3800

= ^{8 × 3800}/₁₀₀

= ³⁰⁴⁰⁰/₁₀₀ = $304

Thus, simple interest for 1 year = $304

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $304 × 2 = $608

Thus, Simple Interest (SI) = $608

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3800 + $608

= $4408

Thus, Amount to be paid = $4408 Answer

Similar Questions

(1) David took a loan of $4800 at the rate of 9% simple interest per annum. If he paid an amount of $8256 to clear the loan, then find the time period of the loan.

(2) Sandra took a loan of $6900 at the rate of 10% simple interest per annum. If he paid an amount of $11730 to clear the loan, then find the time period of the loan.

(3) Michael took a loan of $4600 at the rate of 8% simple interest per annum. If he paid an amount of $7176 to clear the loan, then find the time period of the loan.

(4) Calculate the amount due if Elizabeth borrowed a sum of $3450 at 6% simple interest for 3 years.

(5) Karen took a loan of $5900 at the rate of 7% simple interest per annum. If he paid an amount of $9617 to clear the loan, then find the time period of the loan.

(6) What amount will be due after 2 years if Daniel borrowed a sum of $3550 at a 8% simple interest?

(7) Elizabeth had to pay $3760.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(8) What amount will be due after 2 years if Michael borrowed a sum of $3150 at a 5% simple interest?

(9) Calculate the amount due after 9 years if Linda borrowed a sum of $5350 at a rate of 10% simple interest.

(10) Calculate the amount due after 9 years if Patricia borrowed a sum of $5150 at a rate of 5% simple interest.