Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Jennifer borrowed a sum of $5250 at a rate of 10% simple interest.

Correct Answer  $10500

Solution & Explanation

Solution

Given,

Principal (P) = $5250

Rate of Simple Interest (SI) = 10%

Time (t) = 10 years

Thus, Amount (A) = ?

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

Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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) = $5250 × 10% × 10

= $5250 ×¹⁰/₁₀₀ × 10

= ^{5250 × 10 × 10}/₁₀₀

= ^{52500 × 10}/₁₀₀

= ⁵²⁵⁰⁰⁰/₁₀₀

= $5250

Thus, Simple Interest = $5250

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 = $5250 + $5250

= $10500

Thus, Amount to be paid = $10500 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 = $5250

Rate of Simple Interest (SI) or (R) = 10%

And, Time (t) = 10 years

Thus, Amount (A)

= $5250 + ($5250 × 10% × 10)

= $5250 + ($5250 ×¹⁰/₁₀₀ × 10)

= $5250 + (^{5250 × 10 × 10}/₁₀₀)

= $5250 + (^{52500 × 10}/₁₀₀)

= $5250 + (⁵²⁵⁰⁰⁰/₁₀₀)

= $5250 + $5250 = $10500

Thus, Amount (A) to be paid = $10500 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 10%

This, means, $10 per $100 per year

∵ For $100, the simple interest for 1 year = $10

∴ For $1, the simple interest for 1 year = ¹⁰/₁₀₀

∴ For $5250, the simple interest in 1 year

= ¹⁰/₁₀₀ × 5250

= ^{10 × 5250}/₁₀₀

= ⁵²⁵⁰⁰/₁₀₀ = $525

Thus, simple interest for 1 year = $525

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $525 × 10 = $5250

Thus, Simple Interest (SI) = $5250

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5250 + $5250

= $10500

Thus, Amount to be paid = $10500 Answer

Similar Questions

(1) In how much time a principal of $3050 will amount to $3355 at a simple interest of 2% per annum?

(2) What amount will be due after 2 years if James borrowed a sum of $3000 at a 9% simple interest?

(3) William took a loan of $5000 at the rate of 8% simple interest per annum. If he paid an amount of $9000 to clear the loan, then find the time period of the loan.

(4) Calculate the amount due if Karen borrowed a sum of $3950 at 6% simple interest for 4 years.

(5) Donald took a loan of $7000 at the rate of 10% simple interest per annum. If he paid an amount of $12600 to clear the loan, then find the time period of the loan.

(6) Thomas took a loan of $5600 at the rate of 8% simple interest per annum. If he paid an amount of $9632 to clear the loan, then find the time period of the loan.

(7) Sarah took a loan of $5700 at the rate of 10% simple interest per annum. If he paid an amount of $11400 to clear the loan, then find the time period of the loan.

(8) Kenneth had to pay $5750 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(9) James took a loan of $4000 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.

(10) Mark took a loan of $6800 at the rate of 10% simple interest per annum. If he paid an amount of $10880 to clear the loan, then find the time period of the loan.