Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Mary borrowed a sum of $5050 at a rate of 4% simple interest.

Correct Answer  $7070

Solution & Explanation

Solution

Given,

Principal (P) = $5050

Rate of Simple Interest (SI) = 4%

Time (t) = 10 years

Thus, Amount (A) = ?

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

Thus, here 4% simple interest means, Rate of Simple Interest (SI) is 4% 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) = $5050 × 4% × 10

= $5050 ×⁴/₁₀₀ × 10

= ^{5050 × 4 × 10}/₁₀₀

= ^{20200 × 10}/₁₀₀

= ²⁰²⁰⁰⁰/₁₀₀

= $2020

Thus, Simple Interest = $2020

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 = $5050 + $2020

= $7070

Thus, Amount to be paid = $7070 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 = $5050

Rate of Simple Interest (SI) or (R) = 4%

And, Time (t) = 10 years

Thus, Amount (A)

= $5050 + ($5050 × 4% × 10)

= $5050 + ($5050 ×⁴/₁₀₀ × 10)

= $5050 + (^{5050 × 4 × 10}/₁₀₀)

= $5050 + (^{20200 × 10}/₁₀₀)

= $5050 + (²⁰²⁰⁰⁰/₁₀₀)

= $5050 + $2020 = $7070

Thus, Amount (A) to be paid = $7070 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 4%

This, means, $4 per $100 per year

∵ For $100, the simple interest for 1 year = $4

∴ For $1, the simple interest for 1 year = ⁴/₁₀₀

∴ For $5050, the simple interest in 1 year

= ⁴/₁₀₀ × 5050

= ^{4 × 5050}/₁₀₀

= ²⁰²⁰⁰/₁₀₀ = $202

Thus, simple interest for 1 year = $202

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $202 × 10 = $2020

Thus, Simple Interest (SI) = $2020

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5050 + $2020

= $7070

Thus, Amount to be paid = $7070 Answer

Similar Questions

(1) What amount does Robert have to pay after 5 years if he takes a loan of $3100 at 2% simple interest?

(2) What amount does William have to pay after 6 years if he takes a loan of $3500 at 9% simple interest?

(3) If Elizabeth paid $3864 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(4) Calculate the amount due if Michael borrowed a sum of $3300 at 7% simple interest for 3 years.

(5) Calculate the amount due after 10 years if Joseph borrowed a sum of $5700 at a rate of 2% simple interest.

(6) Calculate the amount due if Patricia borrowed a sum of $3150 at 9% simple interest for 4 years.

(7) Calculate the amount due if John borrowed a sum of $3200 at 8% simple interest for 4 years.

(8) Find the amount to be paid if Christopher borrowed a sum of $6000 at 4% simple interest for 8 years.

(9) Jessica took a loan of $5500 at the rate of 7% simple interest per annum. If he paid an amount of $9350 to clear the loan, then find the time period of the loan.

(10) James took a loan of $4000 at the rate of 10% simple interest per annum. If he paid an amount of $7200 to clear the loan, then find the time period of the loan.