Simple Interest
Math MCQs

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

Correct Answer  $3906

Solution & Explanation

Solution

Given,

Principal (P) = $3150

Rate of Simple Interest (SI) = 6%

Time (t) = 4 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) = $3150 × 6% × 4

= $3150 ×⁶/₁₀₀ × 4

= ^{3150 × 6 × 4}/₁₀₀

= ^{18900 × 4}/₁₀₀

= ⁷⁵⁶⁰⁰/₁₀₀

= $756

Thus, Simple Interest = $756

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 = $3150 + $756

= $3906

Thus, Amount to be paid = $3906 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 = $3150

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

And, Time (t) = 4 years

Thus, Amount (A)

= $3150 + ($3150 × 6% × 4)

= $3150 + ($3150 ×⁶/₁₀₀ × 4)

= $3150 + (^{3150 × 6 × 4}/₁₀₀)

= $3150 + (^{18900 × 4}/₁₀₀)

= $3150 + (⁷⁵⁶⁰⁰/₁₀₀)

= $3150 + $756 = $3906

Thus, Amount (A) to be paid = $3906 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 $3150, the simple interest in 1 year

= ⁶/₁₀₀ × 3150

= ^{6 × 3150}/₁₀₀

= ¹⁸⁹⁰⁰/₁₀₀ = $189

Thus, simple interest for 1 year = $189

Therefore, simple interest for 4 years

= Simple interest for 1 year × 4

= $189 × 4 = $756

Thus, Simple Interest (SI) = $756

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3150 + $756

= $3906

Thus, Amount to be paid = $3906 Answer

Similar Questions

(1) Calculate the amount due if Linda borrowed a sum of $3350 at 2% simple interest for 4 years.

(2) If Lisa paid $4860 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(3) Barbara took a loan of $5100 at the rate of 6% simple interest per annum. If he paid an amount of $7242 to clear the loan, then find the time period of the loan.

(4) Karen took a loan of $5900 at the rate of 9% simple interest per annum. If he paid an amount of $11210 to clear the loan, then find the time period of the loan.

(5) Calculate the amount due after 10 years if Patricia borrowed a sum of $5150 at a rate of 8% simple interest.

(6) What amount does Susan have to pay after 6 years if he takes a loan of $3650 at 6% simple interest?

(7) Michael took a loan of $4600 at the rate of 7% simple interest per annum. If he paid an amount of $7176 to clear the loan, then find the time period of the loan.

(8) Calculate the amount due if Robert borrowed a sum of $3100 at 9% simple interest for 3 years.

(9) If Charles paid $4524 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(10) Find the amount to be paid if Thomas borrowed a sum of $5800 at 10% simple interest for 8 years.