Simple Interest
Math MCQs

Question :    What amount will be due after 2 years if Anthony borrowed a sum of $3650 at a 5% simple interest?

Correct Answer  $4015

Solution & Explanation

Solution

Given,

Principal (P) = $3650

Rate of Simple Interest (SI) = 5%

Time (t) = 2 years

Thus, Amount (A) = ?

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

Thus, here 5% simple interest means, Rate of Simple Interest (SI) is 5% 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) = $3650 × 5% × 2

= $3650 ×⁵/₁₀₀ × 2

= ^{3650 × 5 × 2}/₁₀₀

= ^{18250 × 2}/₁₀₀

= ³⁶⁵⁰⁰/₁₀₀

= $365

Thus, Simple Interest = $365

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 = $3650 + $365

= $4015

Thus, Amount to be paid = $4015 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 = $3650

Rate of Simple Interest (SI) or (R) = 5%

And, Time (t) = 2 years

Thus, Amount (A)

= $3650 + ($3650 × 5% × 2)

= $3650 + ($3650 ×⁵/₁₀₀ × 2)

= $3650 + (^{3650 × 5 × 2}/₁₀₀)

= $3650 + (^{18250 × 2}/₁₀₀)

= $3650 + (³⁶⁵⁰⁰/₁₀₀)

= $3650 + $365 = $4015

Thus, Amount (A) to be paid = $4015 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 5%

This, means, $5 per $100 per year

∵ For $100, the simple interest for 1 year = $5

∴ For $1, the simple interest for 1 year = ⁵/₁₀₀

∴ For $3650, the simple interest in 1 year

= ⁵/₁₀₀ × 3650

= ^{5 × 3650}/₁₀₀

= ¹⁸²⁵⁰/₁₀₀ = $182.5

Thus, simple interest for 1 year = $182.5

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $182.5 × 2 = $365

Thus, Simple Interest (SI) = $365

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3650 + $365

= $4015

Thus, Amount to be paid = $4015 Answer

Similar Questions

(1) In how much time a principal of $3100 will amount to $3379 at a simple interest of 3% per annum?

(2) If John paid $3712 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

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

(4) Find the amount to be paid if Mary borrowed a sum of $5050 at 5% simple interest for 7 years.

(5) Joseph took a loan of $5400 at the rate of 10% simple interest per annum. If he paid an amount of $8640 to clear the loan, then find the time period of the loan.

(6) William took a loan of $5000 at the rate of 8% simple interest per annum. If he paid an amount of $9000 to clear the loan, then find the time period of the loan.

(7) Susan took a loan of $5300 at the rate of 8% simple interest per annum. If he paid an amount of $8692 to clear the loan, then find the time period of the loan.

(8) If Steven paid $5520 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(9) Find the amount to be paid if Christopher borrowed a sum of $6000 at 10% simple interest for 7 years.

(10) Calculate the amount due if Michael borrowed a sum of $3300 at 9% simple interest for 4 years.