Simple Interest
Math MCQs

Question :    If Mary borrowed $3050 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

Correct Answer  $3172

Solution & Explanation

Solution

Given,

Principal (P) = $3050

Rate of Simple Interest (SI) = 2%

Time (t) = 2 years

Thus, Amount (A) = ?

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

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

= $3050 ײ/₁₀₀ × 2

= ^{3050 × 2 × 2}/₁₀₀

= ^{6100 × 2}/₁₀₀

= ¹²²⁰⁰/₁₀₀

= $122

Thus, Simple Interest = $122

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 + $122

= $3172

Thus, Amount to be paid = $3172 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) = 2%

And, Time (t) = 2 years

Thus, Amount (A)

= $3050 + ($3050 × 2% × 2)

= $3050 + ($3050 ײ/₁₀₀ × 2)

= $3050 + (^{3050 × 2 × 2}/₁₀₀)

= $3050 + (^{6100 × 2}/₁₀₀)

= $3050 + (¹²²⁰⁰/₁₀₀)

= $3050 + $122 = $3172

Thus, Amount (A) to be paid = $3172 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 2%

This, means, $2 per $100 per year

∵ For $100, the simple interest in 1 year = $2

∴ For $1, the simple interest in 1 year = ²/₁₀₀

∴ For $3050, the simple interest in 1 year

= ²/₁₀₀ × 3050

= ^{2 × 3050}/₁₀₀

= ⁶¹⁰⁰/₁₀₀ = $61

Thus, simple interest in 1 year = $61

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $61 × 2 = $122

Thus, Simple Interest (SI) = $122

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3050 + $122

= $3172

Thus, Amount to be paid = $3172 Answer

Similar Questions

(1) What amount will be due after 2 years if Andrew borrowed a sum of $3900 at a 10% simple interest?

(2) Calculate the amount due after 9 years if Richard borrowed a sum of $5600 at a rate of 8% simple interest.

(3) How much loan did Steven borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $7260 to clear it?

(4) If Patricia borrowed $3150 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(5) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 6% simple interest for 8 years.

(6) Find the amount to be paid if Jessica borrowed a sum of $5750 at 3% simple interest for 8 years.

(7) Daniel took a loan of $6200 at the rate of 10% simple interest per annum. If he paid an amount of $11160 to clear the loan, then find the time period of the loan.

(8) Calculate the amount due if Robert borrowed a sum of $3100 at 7% simple interest for 4 years.

(9) Calculate the amount due if Joseph borrowed a sum of $3700 at 7% simple interest for 4 years.

(10) Calculate the amount due if Thomas borrowed a sum of $3800 at 6% simple interest for 3 years.