Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Charles borrowed a sum of $5900 at a rate of 9% simple interest.

Correct Answer  $11210

Solution & Explanation

Solution

Given,

Principal (P) = $5900

Rate of Simple Interest (SI) = 9%

Time (t) = 10 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) = $5900 × 9% × 10

= $5900 ×⁹/₁₀₀ × 10

= ^{5900 × 9 × 10}/₁₀₀

= ^{53100 × 10}/₁₀₀

= ⁵³¹⁰⁰⁰/₁₀₀

= $5310

Thus, Simple Interest = $5310

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 = $5900 + $5310

= $11210

Thus, Amount to be paid = $11210 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 = $5900

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

And, Time (t) = 10 years

Thus, Amount (A)

= $5900 + ($5900 × 9% × 10)

= $5900 + ($5900 ×⁹/₁₀₀ × 10)

= $5900 + (^{5900 × 9 × 10}/₁₀₀)

= $5900 + (^{53100 × 10}/₁₀₀)

= $5900 + (⁵³¹⁰⁰⁰/₁₀₀)

= $5900 + $5310 = $11210

Thus, Amount (A) to be paid = $11210 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 $5900, the simple interest in 1 year

= ⁹/₁₀₀ × 5900

= ^{9 × 5900}/₁₀₀

= ⁵³¹⁰⁰/₁₀₀ = $531

Thus, simple interest for 1 year = $531

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $531 × 10 = $5310

Thus, Simple Interest (SI) = $5310

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5900 + $5310

= $11210

Thus, Amount to be paid = $11210 Answer

Similar Questions

(1) Calculate the amount due after 9 years if Karen borrowed a sum of $5950 at a rate of 9% simple interest.

(2) If Donald paid $4860 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(3) Find the amount to be paid if Michael borrowed a sum of $5300 at 2% simple interest for 8 years.

(4) Find the amount to be paid if Susan borrowed a sum of $5650 at 10% simple interest for 8 years.

(5) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 6% simple interest?

(6) How much loan did Amanda borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $8580 to clear it?

(7) Lisa took a loan of $6100 at the rate of 10% simple interest per annum. If he paid an amount of $11590 to clear the loan, then find the time period of the loan.

(8) In how much time a principal of $3000 will amount to $3180 at a simple interest of 3% per annum?

(9) Calculate the amount due after 10 years if Jennifer borrowed a sum of $5250 at a rate of 2% simple interest.

(10) Find the amount to be paid if Michael borrowed a sum of $5300 at 7% simple interest for 7 years.