Simple Interest
Math MCQs

Question :  ( 1 of 10 )  Calculate the amount due if Michael borrowed a sum of $3300 at 5% simple interest for 4 years.

Correct Answer  $3960

Solution & Explanation

Solution

Given,

Principal (P) = $3300

Rate of Simple Interest (SI) = 5%

Time (t) = 4 years

Thus, Amount (A) = ?

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

Thus, here 5% simple interest means, Rate of Simple Interest (SI) is 5% 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) = $3300 × 5% × 4

= $3300 ×⁵/₁₀₀ × 4

= ^{3300 × 5 × 4}/₁₀₀

= ^{16500 × 4}/₁₀₀

= ⁶⁶⁰⁰⁰/₁₀₀

= $660

Thus, Simple Interest = $660

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 = $3300 + $660

= $3960

Thus, Amount to be paid = $3960 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 = $3300

Rate of Simple Interest (SI) or (R) = 5%

And, Time (t) = 4 years

Thus, Amount (A)

= $3300 + ($3300 × 5% × 4)

= $3300 + ($3300 ×⁵/₁₀₀ × 4)

= $3300 + (^{3300 × 5 × 4}/₁₀₀)

= $3300 + (^{16500 × 4}/₁₀₀)

= $3300 + (⁶⁶⁰⁰⁰/₁₀₀)

= $3300 + $660 = $3960

Thus, Amount (A) to be paid = $3960 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 5%

This, means, $5 per $100 per year

∵ For $100, the simple interest for 1 year = $5

∴ For $1, the simple interest for 1 year = ⁵/₁₀₀

∴ For $3300, the simple interest in 1 year

= ⁵/₁₀₀ × 3300

= ^{5 × 3300}/₁₀₀

= ¹⁶⁵⁰⁰/₁₀₀ = $165

Thus, simple interest for 1 year = $165

Therefore, simple interest for 4 years

= Simple interest for 1 year × 4

= $165 × 4 = $660

Thus, Simple Interest (SI) = $660

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3300 + $660

= $3960

Thus, Amount to be paid = $3960 Answer

Similar Questions

(1) What amount will be due after 2 years if Joseph borrowed a sum of $3350 at a 6% simple interest?

(2) Calculate the amount due after 10 years if Karen borrowed a sum of $5950 at a rate of 8% simple interest.

(3) What amount will be due after 2 years if William borrowed a sum of $3250 at a 7% simple interest?

(4) Find the amount to be paid if Christopher borrowed a sum of $6000 at 2% simple interest for 7 years.

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

(6) What amount does Patricia have to pay after 5 years if he takes a loan of $3150 at 4% simple interest?

(7) William took a loan of $5000 at the rate of 10% simple interest per annum. If he paid an amount of $8000 to clear the loan, then find the time period of the loan.

(8) If James paid $3600 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(9) What amount does David have to pay after 6 years if he takes a loan of $3400 at 5% simple interest?

(10) Anthony took a loan of $6600 at the rate of 6% simple interest per annum. If he paid an amount of $9768 to clear the loan, then find the time period of the loan.