Simple Interest
Math MCQs

Question :    Find the amount to be paid if Richard borrowed a sum of $5600 at 3% simple interest for 8 years.

Correct Answer  $6944

Solution & Explanation

Solution

Given,

Principal (P) = $5600

Rate of Simple Interest (SI) = 3%

Time (t) = 8 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% × 8

= $5600 ׳/₁₀₀ × 8

= ^{5600 × 3 × 8}/₁₀₀

= ^{16800 × 8}/₁₀₀

= ¹³⁴⁴⁰⁰/₁₀₀

= $1344

Thus, Simple Interest = $1344

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 + $1344

= $6944

Thus, Amount to be paid = $6944 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) = 8 years

Thus, Amount (A)

= $5600 + ($5600 × 3% × 8)

= $5600 + ($5600 ׳/₁₀₀ × 8)

= $5600 + (^{5600 × 3 × 8}/₁₀₀)

= $5600 + (^{16800 × 8}/₁₀₀)

= $5600 + (¹³⁴⁴⁰⁰/₁₀₀)

= $5600 + $1344 = $6944

Thus, Amount (A) to be paid = $6944 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 8 years

= Simple interest for 1 year × 8

= $168 × 8 = $1344

Thus, Simple Interest (SI) = $1344

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5600 + $1344

= $6944

Thus, Amount to be paid = $6944 Answer

Similar Questions

(1) Thomas took a loan of $5600 at the rate of 10% simple interest per annum. If he paid an amount of $10080 to clear the loan, then find the time period of the loan.

(2) Calculate the amount due after 9 years if James borrowed a sum of $5000 at a rate of 6% simple interest.

(3) David took a loan of $4800 at the rate of 6% simple interest per annum. If he paid an amount of $7104 to clear the loan, then find the time period of the loan.

(4) Jessica took a loan of $5500 at the rate of 6% simple interest per annum. If he paid an amount of $8800 to clear the loan, then find the time period of the loan.

(5) Calculate the amount due after 9 years if Elizabeth borrowed a sum of $5450 at a rate of 3% simple interest.

(6) Find the amount to be paid if Robert borrowed a sum of $5100 at 2% simple interest for 8 years.

(7) If Barbara paid $4260 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(8) Sarah took a loan of $5700 at the rate of 6% simple interest per annum. If he paid an amount of $7752 to clear the loan, then find the time period of the loan.

(9) How much loan did Jason borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $9625 to clear it?

(10) Betty took a loan of $6500 at the rate of 6% simple interest per annum. If he paid an amount of $10400 to clear the loan, then find the time period of the loan.