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) Calculate the amount due if Linda borrowed a sum of $3350 at 7% simple interest for 3 years.

(2) In how much time a principal of $3150 will amount to $3339 at a simple interest of 2% per annum?

(3) What amount will be due after 2 years if James borrowed a sum of $3000 at a 9% simple interest?

(4) Find the amount to be paid if Linda borrowed a sum of $5350 at 5% simple interest for 7 years.

(5) If Lisa paid $4536 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(6) Find the amount to be paid if Michael borrowed a sum of $5300 at 9% simple interest for 7 years.

(7) Michael had to pay $3597 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(8) What amount does Richard have to pay after 6 years if he takes a loan of $3600 at 8% simple interest?

(9) Find the amount to be paid if James borrowed a sum of $5000 at 10% simple interest for 7 years.

(10) Find the amount to be paid if Michael borrowed a sum of $5300 at 6% simple interest for 7 years.