Simple Interest
Math MCQs

Question :    Calculate the amount due after 9 years if Michael borrowed a sum of $5300 at a rate of 9% simple interest.

Correct Answer  $9593

Solution & Explanation

Solution

Given,

Principal (P) = $5300

Rate of Simple Interest (SI) = 9%

Time (t) = 9 years

Thus, Amount (A) = ?

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

Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% 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) = $5300 × 9% × 9

= $5300 ×⁹/₁₀₀ × 9

= ^{5300 × 9 × 9}/₁₀₀

= ^{47700 × 9}/₁₀₀

= ⁴²⁹³⁰⁰/₁₀₀

= $4293

Thus, Simple Interest = $4293

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 = $5300 + $4293

= $9593

Thus, Amount to be paid = $9593 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 = $5300

Rate of Simple Interest (SI) or (R) = 9%

And, Time (t) = 9 years

Thus, Amount (A)

= $5300 + ($5300 × 9% × 9)

= $5300 + ($5300 ×⁹/₁₀₀ × 9)

= $5300 + (^{5300 × 9 × 9}/₁₀₀)

= $5300 + (^{47700 × 9}/₁₀₀)

= $5300 + (⁴²⁹³⁰⁰/₁₀₀)

= $5300 + $4293 = $9593

Thus, Amount (A) to be paid = $9593 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 9%

This, means, $9 per $100 per year

∵ For $100, the simple interest for 1 year = $9

∴ For $1, the simple interest for 1 year = ⁹/₁₀₀

∴ For $5300, the simple interest in 1 year

= ⁹/₁₀₀ × 5300

= ^{9 × 5300}/₁₀₀

= ⁴⁷⁷⁰⁰/₁₀₀ = $477

Thus, simple interest for 1 year = $477

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $477 × 9 = $4293

Thus, Simple Interest (SI) = $4293

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5300 + $4293

= $9593

Thus, Amount to be paid = $9593 Answer

Similar Questions

(1) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 2% simple interest for 7 years.

(2) If Mary paid $3660 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(3) Calculate the amount due after 9 years if Elizabeth borrowed a sum of $5450 at a rate of 9% simple interest.

(4) Calculate the amount due if Richard borrowed a sum of $3600 at 3% simple interest for 4 years.

(5) What amount will be due after 2 years if Joshua borrowed a sum of $3950 at a 10% simple interest?

(6) If Daniel paid $4756 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(7) Linda took a loan of $4700 at the rate of 6% simple interest per annum. If he paid an amount of $6392 to clear the loan, then find the time period of the loan.

(8) Joseph had to pay $3922 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(9) In how much time a principal of $3200 will amount to $3840 at a simple interest of 5% per annum?

(10) Find the amount to be paid if Robert borrowed a sum of $5100 at 5% simple interest for 7 years.