Simple Interest
Math MCQs

Question :  ( 1 of 10 )  Calculate the amount due if David borrowed a sum of $3400 at 6% simple interest for 3 years.

Correct Answer  $4012

Solution & Explanation

Solution

Given,

Principal (P) = $3400

Rate of Simple Interest (SI) = 6%

Time (t) = 3 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) = $3400 × 6% × 3

= $3400 ×⁶/₁₀₀ × 3

= ^{3400 × 6 × 3}/₁₀₀

= ^{20400 × 3}/₁₀₀

= ⁶¹²⁰⁰/₁₀₀

= $612

Thus, Simple Interest = $612

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 = $3400 + $612

= $4012

Thus, Amount to be paid = $4012 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 = $3400

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

And, Time (t) = 3 years

Thus, Amount (A)

= $3400 + ($3400 × 6% × 3)

= $3400 + ($3400 ×⁶/₁₀₀ × 3)

= $3400 + (^{3400 × 6 × 3}/₁₀₀)

= $3400 + (^{20400 × 3}/₁₀₀)

= $3400 + (⁶¹²⁰⁰/₁₀₀)

= $3400 + $612 = $4012

Thus, Amount (A) to be paid = $4012 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 $3400, the simple interest in 1 year

= ⁶/₁₀₀ × 3400

= ^{6 × 3400}/₁₀₀

= ²⁰⁴⁰⁰/₁₀₀ = $204

Thus, simple interest for 1 year = $204

Therefore, simple interest for 3 years

= Simple interest for 1 year × 3

= $204 × 3 = $612

Thus, Simple Interest (SI) = $612

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3400 + $612

= $4012

Thus, Amount to be paid = $4012 Answer

Similar Questions

(1) In how much time a principal of $3100 will amount to $3596 at a simple interest of 4% per annum?

(2) Elizabeth had to pay $3760.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(3) Sandra took a loan of $6900 at the rate of 7% simple interest per annum. If he paid an amount of $9798 to clear the loan, then find the time period of the loan.

(4) Find the amount to be paid if Thomas borrowed a sum of $5800 at 9% simple interest for 7 years.

(5) Calculate the amount due if Michael borrowed a sum of $3300 at 4% simple interest for 3 years.

(6) If Karen paid $4424 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(7) Find the amount to be paid if Sarah borrowed a sum of $5850 at 9% simple interest for 8 years.

(8) What amount does James have to pay after 6 years if he takes a loan of $3000 at 7% simple interest?

(9) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 3% simple interest?

(10) Calculate the amount due if Robert borrowed a sum of $3100 at 6% simple interest for 3 years.