Simple Interest
Math MCQs

Question :    Find the amount to be paid if Charles borrowed a sum of $5900 at 3% simple interest for 8 years.

Correct Answer  $7316

Solution & Explanation

Solution

Given,

Principal (P) = $5900

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) = $5900 × 3% × 8

= $5900 ׳/₁₀₀ × 8

= ^{5900 × 3 × 8}/₁₀₀

= ^{17700 × 8}/₁₀₀

= ¹⁴¹⁶⁰⁰/₁₀₀

= $1416

Thus, Simple Interest = $1416

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 = $5900 + $1416

= $7316

Thus, Amount to be paid = $7316 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 = $5900

Rate of Simple Interest (SI) or (R) = 3%

And, Time (t) = 8 years

Thus, Amount (A)

= $5900 + ($5900 × 3% × 8)

= $5900 + ($5900 ׳/₁₀₀ × 8)

= $5900 + (^{5900 × 3 × 8}/₁₀₀)

= $5900 + (^{17700 × 8}/₁₀₀)

= $5900 + (¹⁴¹⁶⁰⁰/₁₀₀)

= $5900 + $1416 = $7316

Thus, Amount (A) to be paid = $7316 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 $5900, the simple interest in 1 year

= ³/₁₀₀ × 5900

= ^{3 × 5900}/₁₀₀

= ¹⁷⁷⁰⁰/₁₀₀ = $177

Thus, simple interest for 1 year = $177

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $177 × 8 = $1416

Thus, Simple Interest (SI) = $1416

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5900 + $1416

= $7316

Thus, Amount to be paid = $7316 Answer

Similar Questions

(1) Calculate the amount due if John borrowed a sum of $3200 at 7% simple interest for 3 years.

(2) What amount will be due after 2 years if David borrowed a sum of $3200 at a 6% simple interest?

(3) Calculate the amount due if Michael borrowed a sum of $3300 at 6% simple interest for 3 years.

(4) In how much time a principal of $3200 will amount to $3520 at a simple interest of 2% per annum?

(5) If David borrowed $3400 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.

(6) Calculate the amount due after 10 years if Christopher borrowed a sum of $6000 at a rate of 9% simple interest.

(7) William took a loan of $5000 at the rate of 7% simple interest per annum. If he paid an amount of $7450 to clear the loan, then find the time period of the loan.

(8) Calculate the amount due if Susan borrowed a sum of $3650 at 4% simple interest for 4 years.

(9) Richard took a loan of $5200 at the rate of 6% simple interest per annum. If he paid an amount of $7384 to clear the loan, then find the time period of the loan.

(10) If Karen paid $4266 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.