Simple Interest
Math MCQs

Question :    What amount will be due after 2 years if Mark borrowed a sum of $3700 at a 10% simple interest?

Correct Answer  $4440

Solution & Explanation

Solution

Given,

Principal (P) = $3700

Rate of Simple Interest (SI) = 10%

Time (t) = 2 years

Thus, Amount (A) = ?

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

Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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) = $3700 × 10% × 2

= $3700 ×¹⁰/₁₀₀ × 2

= ^{3700 × 10 × 2}/₁₀₀

= ^{37000 × 2}/₁₀₀

= ⁷⁴⁰⁰⁰/₁₀₀

= $740

Thus, Simple Interest = $740

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 = $3700 + $740

= $4440

Thus, Amount to be paid = $4440 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 = $3700

Rate of Simple Interest (SI) or (R) = 10%

And, Time (t) = 2 years

Thus, Amount (A)

= $3700 + ($3700 × 10% × 2)

= $3700 + ($3700 ×¹⁰/₁₀₀ × 2)

= $3700 + (^{3700 × 10 × 2}/₁₀₀)

= $3700 + (^{37000 × 2}/₁₀₀)

= $3700 + (⁷⁴⁰⁰⁰/₁₀₀)

= $3700 + $740 = $4440

Thus, Amount (A) to be paid = $4440 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 10%

This, means, $10 per $100 per year

∵ For $100, the simple interest for 1 year = $10

∴ For $1, the simple interest for 1 year = ¹⁰/₁₀₀

∴ For $3700, the simple interest in 1 year

= ¹⁰/₁₀₀ × 3700

= ^{10 × 3700}/₁₀₀

= ³⁷⁰⁰⁰/₁₀₀ = $370

Thus, simple interest for 1 year = $370

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $370 × 2 = $740

Thus, Simple Interest (SI) = $740

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3700 + $740

= $4440

Thus, Amount to be paid = $4440 Answer

Similar Questions

(1) Calculate the amount due after 9 years if Jennifer borrowed a sum of $5250 at a rate of 5% simple interest.

(2) Calculate the amount due if Robert borrowed a sum of $3100 at 8% simple interest for 3 years.

(3) Calculate the amount due after 10 years if Mary borrowed a sum of $5050 at a rate of 6% simple interest.

(4) If James borrowed $3000 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.

(5) James took a loan of $4000 at the rate of 8% simple interest per annum. If he paid an amount of $5920 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due if David borrowed a sum of $3400 at 4% simple interest for 3 years.

(7) What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 10% simple interest?

(8) Calculate the amount due if Michael borrowed a sum of $3300 at 5% simple interest for 4 years.

(9) Christopher took a loan of $6000 at the rate of 8% simple interest per annum. If he paid an amount of $9360 to clear the loan, then find the time period of the loan.

(10) Richard took a loan of $5200 at the rate of 9% simple interest per annum. If he paid an amount of $8944 to clear the loan, then find the time period of the loan.