Simple Interest
Math MCQs

Question :    Calculate the amount due after 9 years if Jessica borrowed a sum of $5750 at a rate of 2% simple interest.

Correct Answer  $6785

Solution & Explanation

Solution

Given,

Principal (P) = $5750

Rate of Simple Interest (SI) = 2%

Time (t) = 9 years

Thus, Amount (A) = ?

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

Thus, here 2% simple interest means, Rate of Simple Interest (SI) is 2% 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) = $5750 × 2% × 9

= $5750 ײ/₁₀₀ × 9

= ^{5750 × 2 × 9}/₁₀₀

= ^{11500 × 9}/₁₀₀

= ¹⁰³⁵⁰⁰/₁₀₀

= $1035

Thus, Simple Interest = $1035

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 = $5750 + $1035

= $6785

Thus, Amount to be paid = $6785 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 = $5750

Rate of Simple Interest (SI) or (R) = 2%

And, Time (t) = 9 years

Thus, Amount (A)

= $5750 + ($5750 × 2% × 9)

= $5750 + ($5750 ײ/₁₀₀ × 9)

= $5750 + (^{5750 × 2 × 9}/₁₀₀)

= $5750 + (^{11500 × 9}/₁₀₀)

= $5750 + (¹⁰³⁵⁰⁰/₁₀₀)

= $5750 + $1035 = $6785

Thus, Amount (A) to be paid = $6785 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 2%

This, means, $2 per $100 per year

∵ For $100, the simple interest for 1 year = $2

∴ For $1, the simple interest for 1 year = ²/₁₀₀

∴ For $5750, the simple interest in 1 year

= ²/₁₀₀ × 5750

= ^{2 × 5750}/₁₀₀

= ¹¹⁵⁰⁰/₁₀₀ = $115

Thus, simple interest for 1 year = $115

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $115 × 9 = $1035

Thus, Simple Interest (SI) = $1035

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5750 + $1035

= $6785

Thus, Amount to be paid = $6785 Answer

Similar Questions

(1) How much loan did Jason borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $9240 to clear it?

(2) Find the amount to be paid if Robert borrowed a sum of $5100 at 8% simple interest for 7 years.

(3) What amount does Jessica have to pay after 5 years if he takes a loan of $3750 at 3% simple interest?

(4) Michael took a loan of $4600 at the rate of 9% simple interest per annum. If he paid an amount of $7084 to clear the loan, then find the time period of the loan.

(5) Calculate the amount due if Robert borrowed a sum of $3100 at 6% simple interest for 4 years.

(6) James had to pay $3450 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(7) Calculate the amount due if Charles borrowed a sum of $3900 at 2% simple interest for 4 years.

(8) In how much time a principal of $3100 will amount to $3472 at a simple interest of 3% per annum?

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

(10) Calculate the amount due if Jennifer borrowed a sum of $3250 at 4% simple interest for 3 years.