Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Jennifer borrowed a sum of $5250 at a rate of 6% simple interest.

Correct Answer  $8400

Solution & Explanation

Solution

Given,

Principal (P) = $5250

Rate of Simple Interest (SI) = 6%

Time (t) = 10 years

Thus, Amount (A) = ?

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

Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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 × 6% × 10

= $5250 ×⁶/₁₀₀ × 10

= ^{5250 × 6 × 10}/₁₀₀

= ^{31500 × 10}/₁₀₀

= ³¹⁵⁰⁰⁰/₁₀₀

= $3150

Thus, Simple Interest = $3150

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 + $3150

= $8400

Thus, Amount to be paid = $8400 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) = 6%

And, Time (t) = 10 years

Thus, Amount (A)

= $5250 + ($5250 × 6% × 10)

= $5250 + ($5250 ×⁶/₁₀₀ × 10)

= $5250 + (^{5250 × 6 × 10}/₁₀₀)

= $5250 + (^{31500 × 10}/₁₀₀)

= $5250 + (³¹⁵⁰⁰⁰/₁₀₀)

= $5250 + $3150 = $8400

Thus, Amount (A) to be paid = $8400 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = ⁶/₁₀₀

∴ For $5250, the simple interest in 1 year

= ⁶/₁₀₀ × 5250

= ^{6 × 5250}/₁₀₀

= ³¹⁵⁰⁰/₁₀₀ = $315

Thus, simple interest for 1 year = $315

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $315 × 10 = $3150

Thus, Simple Interest (SI) = $3150

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5250 + $3150

= $8400

Thus, Amount to be paid = $8400 Answer

Similar Questions

(1) Thomas took a loan of $5600 at the rate of 8% simple interest per annum. If he paid an amount of $10080 to clear the loan, then find the time period of the loan.

(2) Sarah took a loan of $5700 at the rate of 10% simple interest per annum. If he paid an amount of $9690 to clear the loan, then find the time period of the loan.

(3) Michael took a loan of $4600 at the rate of 9% simple interest per annum. If he paid an amount of $7912 to clear the loan, then find the time period of the loan.

(4) Find the amount to be paid if Richard borrowed a sum of $5600 at 8% simple interest for 7 years.

(5) Jessica took a loan of $5500 at the rate of 6% simple interest per annum. If he paid an amount of $7480 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due after 9 years if Michael borrowed a sum of $5300 at a rate of 3% simple interest.

(7) Christopher took a loan of $6000 at the rate of 6% simple interest per annum. If he paid an amount of $8160 to clear the loan, then find the time period of the loan.

(8) Anthony took a loan of $6600 at the rate of 7% simple interest per annum. If he paid an amount of $11220 to clear the loan, then find the time period of the loan.

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

(10) Calculate the amount due after 9 years if Susan borrowed a sum of $5650 at a rate of 7% simple interest.