Simple Interest
Math MCQs

Question :    What amount will be due after 2 years if Matthew borrowed a sum of $3600 at a 6% simple interest?

Correct Answer  $4032

Solution & Explanation

Solution

Given,

Principal (P) = $3600

Rate of Simple Interest (SI) = 6%

Time (t) = 2 years

Thus, Amount (A) = ?

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

Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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) = $3600 × 6% × 2

= $3600 ×⁶/₁₀₀ × 2

= ^{3600 × 6 × 2}/₁₀₀

= ^{21600 × 2}/₁₀₀

= ⁴³²⁰⁰/₁₀₀

= $432

Thus, Simple Interest = $432

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 = $3600 + $432

= $4032

Thus, Amount to be paid = $4032 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 = $3600

Rate of Simple Interest (SI) or (R) = 6%

And, Time (t) = 2 years

Thus, Amount (A)

= $3600 + ($3600 × 6% × 2)

= $3600 + ($3600 ×⁶/₁₀₀ × 2)

= $3600 + (^{3600 × 6 × 2}/₁₀₀)

= $3600 + (^{21600 × 2}/₁₀₀)

= $3600 + (⁴³²⁰⁰/₁₀₀)

= $3600 + $432 = $4032

Thus, Amount (A) to be paid = $4032 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = ⁶/₁₀₀

∴ For $3600, the simple interest in 1 year

= ⁶/₁₀₀ × 3600

= ^{6 × 3600}/₁₀₀

= ²¹⁶⁰⁰/₁₀₀ = $216

Thus, simple interest for 1 year = $216

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $216 × 2 = $432

Thus, Simple Interest (SI) = $432

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3600 + $432

= $4032

Thus, Amount to be paid = $4032 Answer

Similar Questions

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

(2) Ashley had to pay $5232.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(3) Christopher took a loan of $6000 at the rate of 9% simple interest per annum. If he paid an amount of $10860 to clear the loan, then find the time period of the loan.

(4) William took a loan of $5000 at the rate of 9% simple interest per annum. If he paid an amount of $7700 to clear the loan, then find the time period of the loan.

(5) Jessica took a loan of $5500 at the rate of 9% simple interest per annum. If he paid an amount of $9955 to clear the loan, then find the time period of the loan.

(6) James took a loan of $4000 at the rate of 9% simple interest per annum. If he paid an amount of $6520 to clear the loan, then find the time period of the loan.

(7) Sandra took a loan of $6900 at the rate of 10% simple interest per annum. If he paid an amount of $12420 to clear the loan, then find the time period of the loan.

(8) John took a loan of $4400 at the rate of 10% simple interest per annum. If he paid an amount of $8800 to clear the loan, then find the time period of the loan.

(9) Find the amount to be paid if David borrowed a sum of $5400 at 8% simple interest for 7 years.

(10) What amount will be due after 2 years if Matthew borrowed a sum of $3600 at a 10% simple interest?