Simple Interest
Math MCQs

Question :    Calculate the amount due if Linda borrowed a sum of $3350 at 2% simple interest for 3 years.

Correct Answer  $3551

Solution & Explanation

Solution

Given,

Principal (P) = $3350

Rate of Simple Interest (SI) = 2%

Time (t) = 3 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) = $3350 × 2% × 3

= $3350 ײ/₁₀₀ × 3

= ^{3350 × 2 × 3}/₁₀₀

= ^{6700 × 3}/₁₀₀

= ²⁰¹⁰⁰/₁₀₀

= $201

Thus, Simple Interest = $201

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 = $3350 + $201

= $3551

Thus, Amount to be paid = $3551 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 = $3350

Rate of Simple Interest (SI) or (R) = 2%

And, Time (t) = 3 years

Thus, Amount (A)

= $3350 + ($3350 × 2% × 3)

= $3350 + ($3350 ײ/₁₀₀ × 3)

= $3350 + (^{3350 × 2 × 3}/₁₀₀)

= $3350 + (^{6700 × 3}/₁₀₀)

= $3350 + (²⁰¹⁰⁰/₁₀₀)

= $3350 + $201 = $3551

Thus, Amount (A) to be paid = $3551 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 for 1 year = $2

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

∴ For $3350, the simple interest in 1 year

= ²/₁₀₀ × 3350

= ^{2 × 3350}/₁₀₀

= ⁶⁷⁰⁰/₁₀₀ = $67

Thus, simple interest for 1 year = $67

Therefore, simple interest for 3 years

= Simple interest for 1 year × 3

= $67 × 3 = $201

Thus, Simple Interest (SI) = $201

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3350 + $201

= $3551

Thus, Amount to be paid = $3551 Answer

Similar Questions

(1) Calculate the amount due if James borrowed a sum of $3000 at 4% simple interest for 4 years.

(2) Calculate the amount due after 9 years if Michael borrowed a sum of $5300 at a rate of 7% simple interest.

(3) What amount will be due after 2 years if Donald borrowed a sum of $3750 at a 7% simple interest?

(4) Calculate the amount due after 10 years if Patricia borrowed a sum of $5150 at a rate of 6% simple interest.

(5) Calculate the amount due after 9 years if David borrowed a sum of $5400 at a rate of 6% simple interest.

(6) Find the amount to be paid if Sarah borrowed a sum of $5850 at 6% simple interest for 8 years.

(7) If James paid $3600 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.

(8) Calculate the amount due after 10 years if Elizabeth borrowed a sum of $5450 at a rate of 7% simple interest.

(9) Michael took a loan of $4600 at the rate of 7% simple interest per annum. If he paid an amount of $7498 to clear the loan, then find the time period of the loan.

(10) Calculate the amount due after 9 years if Barbara borrowed a sum of $5550 at a rate of 5% simple interest.