Simple Interest
Math MCQs

Question :    Calculate the amount due if Joseph borrowed a sum of $3700 at 9% simple interest for 4 years.

Correct Answer  $5032

Solution & Explanation

Solution

Given,

Principal (P) = $3700

Rate of Simple Interest (SI) = 9%

Time (t) = 4 years

Thus, Amount (A) = ?

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

Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% 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 × 9% × 4

= $3700 ×⁹/₁₀₀ × 4

= ^{3700 × 9 × 4}/₁₀₀

= ^{33300 × 4}/₁₀₀

= ¹³³²⁰⁰/₁₀₀

= $1332

Thus, Simple Interest = $1332

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 + $1332

= $5032

Thus, Amount to be paid = $5032 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) = 9%

And, Time (t) = 4 years

Thus, Amount (A)

= $3700 + ($3700 × 9% × 4)

= $3700 + ($3700 ×⁹/₁₀₀ × 4)

= $3700 + (^{3700 × 9 × 4}/₁₀₀)

= $3700 + (^{33300 × 4}/₁₀₀)

= $3700 + (¹³³²⁰⁰/₁₀₀)

= $3700 + $1332 = $5032

Thus, Amount (A) to be paid = $5032 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 9%

This, means, $9 per $100 per year

∵ For $100, the simple interest for 1 year = $9

∴ For $1, the simple interest for 1 year = ⁹/₁₀₀

∴ For $3700, the simple interest in 1 year

= ⁹/₁₀₀ × 3700

= ^{9 × 3700}/₁₀₀

= ³³³⁰⁰/₁₀₀ = $333

Thus, simple interest for 1 year = $333

Therefore, simple interest for 4 years

= Simple interest for 1 year × 4

= $333 × 4 = $1332

Thus, Simple Interest (SI) = $1332

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3700 + $1332

= $5032

Thus, Amount to be paid = $5032 Answer

Similar Questions

(1) What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 9% simple interest?

(2) What amount does Linda have to pay after 6 years if he takes a loan of $3350 at 6% simple interest?

(3) How much loan did Timothy borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $8140 to clear it?

(4) Karen took a loan of $5900 at the rate of 9% simple interest per annum. If he paid an amount of $9086 to clear the loan, then find the time period of the loan.

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

(6) What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 4% simple interest?

(7) Calculate the amount due if Jennifer borrowed a sum of $3250 at 3% simple interest for 3 years.

(8) Find the amount to be paid if Jessica borrowed a sum of $5750 at 6% simple interest for 8 years.

(9) In how much time a principal of $3200 will amount to $3840 at a simple interest of 4% per annum?

(10) Calculate the amount due if Jennifer borrowed a sum of $3250 at 2% simple interest for 3 years.