Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Charles borrowed a sum of $5900 at a rate of 2% simple interest.

Correct Answer  $7080

Solution & Explanation

Solution

Given,

Principal (P) = $5900

Rate of Simple Interest (SI) = 2%

Time (t) = 10 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) = $5900 × 2% × 10

= $5900 ײ/₁₀₀ × 10

= ^{5900 × 2 × 10}/₁₀₀

= ^{11800 × 10}/₁₀₀

= ¹¹⁸⁰⁰⁰/₁₀₀

= $1180

Thus, Simple Interest = $1180

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 + $1180

= $7080

Thus, Amount to be paid = $7080 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) = 2%

And, Time (t) = 10 years

Thus, Amount (A)

= $5900 + ($5900 × 2% × 10)

= $5900 + ($5900 ײ/₁₀₀ × 10)

= $5900 + (^{5900 × 2 × 10}/₁₀₀)

= $5900 + (^{11800 × 10}/₁₀₀)

= $5900 + (¹¹⁸⁰⁰⁰/₁₀₀)

= $5900 + $1180 = $7080

Thus, Amount (A) to be paid = $7080 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 $5900, the simple interest in 1 year

= ²/₁₀₀ × 5900

= ^{2 × 5900}/₁₀₀

= ¹¹⁸⁰⁰/₁₀₀ = $118

Thus, simple interest for 1 year = $118

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $118 × 10 = $1180

Thus, Simple Interest (SI) = $1180

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5900 + $1180

= $7080

Thus, Amount to be paid = $7080 Answer

Similar Questions

(1) Calculate the amount due after 9 years if Charles borrowed a sum of $5900 at a rate of 4% simple interest.

(2) What amount will be due after 2 years if James borrowed a sum of $3000 at a 6% simple interest?

(3) What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 6% simple interest?

(4) How much loan did Paul borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $7370 to clear it?

(5) Mark took a loan of $6800 at the rate of 8% simple interest per annum. If he paid an amount of $11152 to clear the loan, then find the time period of the loan.

(6) How much loan did Patricia borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $5922.5 to clear it?

(7) Calculate the amount due if Christopher borrowed a sum of $4000 at 9% simple interest for 4 years.

(8) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 2% simple interest?

(9) In how much time a principal of $3200 will amount to $3520 at a simple interest of 2% per annum?

(10) Calculate the amount due if Patricia borrowed a sum of $3150 at 10% simple interest for 3 years.