Simple Interest
Math MCQs

Question :    What amount will be due after 2 years if John borrowed a sum of $3100 at a 6% simple interest?

Correct Answer  $3472

Solution & Explanation

Solution

Given,

Principal (P) = $3100

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) = $3100 × 6% × 2

= $3100 ×⁶/₁₀₀ × 2

= ^{3100 × 6 × 2}/₁₀₀

= ^{18600 × 2}/₁₀₀

= ³⁷²⁰⁰/₁₀₀

= $372

Thus, Simple Interest = $372

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 = $3100 + $372

= $3472

Thus, Amount to be paid = $3472 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 = $3100

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

And, Time (t) = 2 years

Thus, Amount (A)

= $3100 + ($3100 × 6% × 2)

= $3100 + ($3100 ×⁶/₁₀₀ × 2)

= $3100 + (^{3100 × 6 × 2}/₁₀₀)

= $3100 + (^{18600 × 2}/₁₀₀)

= $3100 + (³⁷²⁰⁰/₁₀₀)

= $3100 + $372 = $3472

Thus, Amount (A) to be paid = $3472 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 $3100, the simple interest in 1 year

= ⁶/₁₀₀ × 3100

= ^{6 × 3100}/₁₀₀

= ¹⁸⁶⁰⁰/₁₀₀ = $186

Thus, simple interest for 1 year = $186

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $186 × 2 = $372

Thus, Simple Interest (SI) = $372

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3100 + $372

= $3472

Thus, Amount to be paid = $3472 Answer

Similar Questions

(1) What amount does John have to pay after 6 years if he takes a loan of $3200 at 8% simple interest?

(2) Daniel took a loan of $6200 at the rate of 8% simple interest per annum. If he paid an amount of $9672 to clear the loan, then find the time period of the loan.

(3) If William borrowed $3500 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.

(4) What amount does Charles have to pay after 6 years if he takes a loan of $3900 at 9% simple interest?

(5) Matthew had to pay $4452 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(6) Calculate the amount due after 9 years if Thomas borrowed a sum of $5800 at a rate of 8% simple interest.

(7) In how much time a principal of $3050 will amount to $3538 at a simple interest of 4% per annum?

(8) Karen took a loan of $5900 at the rate of 10% simple interest per annum. If he paid an amount of $11210 to clear the loan, then find the time period of the loan.

(9) In how much time a principal of $3050 will amount to $3355 at a simple interest of 2% per annum?

(10) If Christopher paid $4800 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.