Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Jessica borrowed a sum of $5750 at a rate of 3% simple interest.

Correct Answer  $7475

Solution & Explanation

Solution

Given,

Principal (P) = $5750

Rate of Simple Interest (SI) = 3%

Time (t) = 10 years

Thus, Amount (A) = ?

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

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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 × 3% × 10

= $5750 ׳/₁₀₀ × 10

= ^{5750 × 3 × 10}/₁₀₀

= ^{17250 × 10}/₁₀₀

= ¹⁷²⁵⁰⁰/₁₀₀

= $1725

Thus, Simple Interest = $1725

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 + $1725

= $7475

Thus, Amount to be paid = $7475 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) = 3%

And, Time (t) = 10 years

Thus, Amount (A)

= $5750 + ($5750 × 3% × 10)

= $5750 + ($5750 ׳/₁₀₀ × 10)

= $5750 + (^{5750 × 3 × 10}/₁₀₀)

= $5750 + (^{17250 × 10}/₁₀₀)

= $5750 + (¹⁷²⁵⁰⁰/₁₀₀)

= $5750 + $1725 = $7475

Thus, Amount (A) to be paid = $7475 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = ³/₁₀₀

∴ For $5750, the simple interest in 1 year

= ³/₁₀₀ × 5750

= ^{3 × 5750}/₁₀₀

= ¹⁷²⁵⁰/₁₀₀ = $172.5

Thus, simple interest for 1 year = $172.5

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $172.5 × 10 = $1725

Thus, Simple Interest (SI) = $1725

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5750 + $1725

= $7475

Thus, Amount to be paid = $7475 Answer

Similar Questions

(1) Calculate the amount due if Jessica borrowed a sum of $3750 at 10% simple interest for 3 years.

(2) Calculate the amount due if Patricia borrowed a sum of $3150 at 4% simple interest for 4 years.

(3) How much loan did Cynthia borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $9142.5 to clear it?

(4) Anthony took a loan of $6600 at the rate of 9% simple interest per annum. If he paid an amount of $12540 to clear the loan, then find the time period of the loan.

(5) Barbara took a loan of $5100 at the rate of 10% simple interest per annum. If he paid an amount of $10200 to clear the loan, then find the time period of the loan.

(6) Find the amount to be paid if William borrowed a sum of $5500 at 9% simple interest for 7 years.

(7) In how much time a principal of $3100 will amount to $3720 at a simple interest of 4% per annum?

(8) Find the amount to be paid if William borrowed a sum of $5500 at 2% simple interest for 8 years.

(9) How much loan did John borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $5980 to clear it?

(10) Mary took a loan of $4100 at the rate of 6% simple interest per annum. If he paid an amount of $6068 to clear the loan, then find the time period of the loan.