Simple Interest
Math MCQs

Question :    What amount will be due after 2 years if Robert borrowed a sum of $3050 at a 6% simple interest?

Correct Answer  $3416

Solution & Explanation

Solution

Given,

Principal (P) = $3050

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) = $3050 × 6% × 2

= $3050 ×⁶/₁₀₀ × 2

= ^{3050 × 6 × 2}/₁₀₀

= ^{18300 × 2}/₁₀₀

= ³⁶⁶⁰⁰/₁₀₀

= $366

Thus, Simple Interest = $366

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 = $3050 + $366

= $3416

Thus, Amount to be paid = $3416 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 = $3050

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

And, Time (t) = 2 years

Thus, Amount (A)

= $3050 + ($3050 × 6% × 2)

= $3050 + ($3050 ×⁶/₁₀₀ × 2)

= $3050 + (^{3050 × 6 × 2}/₁₀₀)

= $3050 + (^{18300 × 2}/₁₀₀)

= $3050 + (³⁶⁶⁰⁰/₁₀₀)

= $3050 + $366 = $3416

Thus, Amount (A) to be paid = $3416 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 $3050, the simple interest in 1 year

= ⁶/₁₀₀ × 3050

= ^{6 × 3050}/₁₀₀

= ¹⁸³⁰⁰/₁₀₀ = $183

Thus, simple interest for 1 year = $183

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $183 × 2 = $366

Thus, Simple Interest (SI) = $366

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3050 + $366

= $3416

Thus, Amount to be paid = $3416 Answer

Similar Questions

(1) Find the amount to be paid if John borrowed a sum of $5200 at 9% simple interest for 7 years.

(2) Calculate the amount due if Richard borrowed a sum of $3600 at 4% simple interest for 4 years.

(3) How much loan did Richard borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6720 to clear it?

(4) If Lisa paid $4374 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(5) Calculate the amount due after 10 years if Linda borrowed a sum of $5350 at a rate of 8% simple interest.

(6) Karen took a loan of $5900 at the rate of 10% simple interest per annum. If he paid an amount of $11800 to clear the loan, then find the time period of the loan.

(7) Margaret took a loan of $6700 at the rate of 8% simple interest per annum. If he paid an amount of $11524 to clear the loan, then find the time period of the loan.

(8) In how much time a principal of $3050 will amount to $3416 at a simple interest of 4% per annum?

(9) Find the amount to be paid if Patricia borrowed a sum of $5150 at 9% simple interest for 8 years.

(10) James took a loan of $4000 at the rate of 8% simple interest per annum. If he paid an amount of $5920 to clear the loan, then find the time period of the loan.