Simple Interest
Math MCQs

Question :    Calculate the amount due if Jennifer borrowed a sum of $3250 at 5% simple interest for 4 years.

Correct Answer  $3900

Solution & Explanation

Solution

Given,

Principal (P) = $3250

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) = $3250 × 5% × 4

= $3250 ×⁵/₁₀₀ × 4

= ^{3250 × 5 × 4}/₁₀₀

= ^{16250 × 4}/₁₀₀

= ⁶⁵⁰⁰⁰/₁₀₀

= $650

Thus, Simple Interest = $650

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 = $3250 + $650

= $3900

Thus, Amount to be paid = $3900 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 = $3250

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

And, Time (t) = 4 years

Thus, Amount (A)

= $3250 + ($3250 × 5% × 4)

= $3250 + ($3250 ×⁵/₁₀₀ × 4)

= $3250 + (^{3250 × 5 × 4}/₁₀₀)

= $3250 + (^{16250 × 4}/₁₀₀)

= $3250 + (⁶⁵⁰⁰⁰/₁₀₀)

= $3250 + $650 = $3900

Thus, Amount (A) to be paid = $3900 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 $3250, the simple interest in 1 year

= ⁵/₁₀₀ × 3250

= ^{5 × 3250}/₁₀₀

= ¹⁶²⁵⁰/₁₀₀ = $162.5

Thus, simple interest for 1 year = $162.5

Therefore, simple interest for 4 years

= Simple interest for 1 year × 4

= $162.5 × 4 = $650

Thus, Simple Interest (SI) = $650

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3250 + $650

= $3900

Thus, Amount to be paid = $3900 Answer

Similar Questions

(1) In how much time a principal of $3000 will amount to $3450 at a simple interest of 3% per annum?

(2) Calculate the amount due if William borrowed a sum of $3500 at 4% simple interest for 4 years.

(3) Calculate the amount due if Jennifer borrowed a sum of $3250 at 2% simple interest for 3 years.

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

(5) Donald took a loan of $7000 at the rate of 7% simple interest per annum. If he paid an amount of $11900 to clear the loan, then find the time period of the loan.

(6) What amount does Linda have to pay after 5 years if he takes a loan of $3350 at 8% simple interest?

(7) What amount does Joseph have to pay after 5 years if he takes a loan of $3700 at 9% simple interest?

(8) What amount does Karen have to pay after 6 years if he takes a loan of $3950 at 5% simple interest?

(9) Calculate the amount due if Charles borrowed a sum of $3900 at 9% simple interest for 3 years.

(10) Calculate the amount due if Thomas borrowed a sum of $3800 at 10% simple interest for 3 years.