Simple Interest
Math MCQs

Question :    What amount will be due after 2 years if John borrowed a sum of $3100 at a 8% simple interest?

Correct Answer  $3596

Solution & Explanation

Solution

Given,

Principal (P) = $3100

Rate of Simple Interest (SI) = 8%

Time (t) = 2 years

Thus, Amount (A) = ?

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

Thus, here 8% simple interest means, Rate of Simple Interest (SI) is 8% 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 × 8% × 2

= $3100 ×⁸/₁₀₀ × 2

= ^{3100 × 8 × 2}/₁₀₀

= ^{24800 × 2}/₁₀₀

= ⁴⁹⁶⁰⁰/₁₀₀

= $496

Thus, Simple Interest = $496

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 + $496

= $3596

Thus, Amount to be paid = $3596 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) = 8%

And, Time (t) = 2 years

Thus, Amount (A)

= $3100 + ($3100 × 8% × 2)

= $3100 + ($3100 ×⁸/₁₀₀ × 2)

= $3100 + (^{3100 × 8 × 2}/₁₀₀)

= $3100 + (^{24800 × 2}/₁₀₀)

= $3100 + (⁴⁹⁶⁰⁰/₁₀₀)

= $3100 + $496 = $3596

Thus, Amount (A) to be paid = $3596 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 8%

This, means, $8 per $100 per year

∵ For $100, the simple interest for 1 year = $8

∴ For $1, the simple interest for 1 year = ⁸/₁₀₀

∴ For $3100, the simple interest in 1 year

= ⁸/₁₀₀ × 3100

= ^{8 × 3100}/₁₀₀

= ²⁴⁸⁰⁰/₁₀₀ = $248

Thus, simple interest for 1 year = $248

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $248 × 2 = $496

Thus, Simple Interest (SI) = $496

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3100 + $496

= $3596

Thus, Amount to be paid = $3596 Answer

Similar Questions

(1) Find the amount to be paid if Richard borrowed a sum of $5600 at 6% simple interest for 7 years.

(2) Calculate the amount due if Joseph borrowed a sum of $3700 at 6% simple interest for 4 years.

(3) In how much time a principal of $3000 will amount to $3180 at a simple interest of 3% per annum?

(4) Calculate the amount due if Barbara borrowed a sum of $3550 at 8% simple interest for 4 years.

(5) If William paid $4060 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(6) David took a loan of $4800 at the rate of 10% simple interest per annum. If he paid an amount of $9600 to clear the loan, then find the time period of the loan.

(7) What amount does Thomas have to pay after 5 years if he takes a loan of $3800 at 4% simple interest?

(8) Ashley had to pay $4959.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(9) If Mary paid $3538 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(10) Daniel took a loan of $6200 at the rate of 6% simple interest per annum. If he paid an amount of $8804 to clear the loan, then find the time period of the loan.