Simple Interest
Math MCQs

Question :    Calculate the amount due after 10 years if Patricia borrowed a sum of $5150 at a rate of 3% simple interest.

Correct Answer  $6695

Solution & Explanation

Solution

Given,

Principal (P) = $5150

Rate of Simple Interest (SI) = 3%

Time (t) = 10 years

Thus, Amount (A) = ?

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

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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) = $5150 × 3% × 10

= $5150 ׳/₁₀₀ × 10

= ^{5150 × 3 × 10}/₁₀₀

= ^{15450 × 10}/₁₀₀

= ¹⁵⁴⁵⁰⁰/₁₀₀

= $1545

Thus, Simple Interest = $1545

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 = $5150 + $1545

= $6695

Thus, Amount to be paid = $6695 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 = $5150

Rate of Simple Interest (SI) or (R) = 3%

And, Time (t) = 10 years

Thus, Amount (A)

= $5150 + ($5150 × 3% × 10)

= $5150 + ($5150 ׳/₁₀₀ × 10)

= $5150 + (^{5150 × 3 × 10}/₁₀₀)

= $5150 + (^{15450 × 10}/₁₀₀)

= $5150 + (¹⁵⁴⁵⁰⁰/₁₀₀)

= $5150 + $1545 = $6695

Thus, Amount (A) to be paid = $6695 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = ³/₁₀₀

∴ For $5150, the simple interest in 1 year

= ³/₁₀₀ × 5150

= ^{3 × 5150}/₁₀₀

= ¹⁵⁴⁵⁰/₁₀₀ = $154.5

Thus, simple interest for 1 year = $154.5

Therefore, simple interest for 10 years

= Simple interest for 1 year × 10

= $154.5 × 10 = $1545

Thus, Simple Interest (SI) = $1545

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5150 + $1545

= $6695

Thus, Amount to be paid = $6695 Answer

Similar Questions

(1) What amount will be due after 2 years if Steven borrowed a sum of $3800 at a 4% simple interest?

(2) What amount will be due after 2 years if Robert borrowed a sum of $3050 at a 9% simple interest?

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

(4) How much loan did Dorothy borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $8700 to clear it?

(5) Find the amount to be paid if James borrowed a sum of $5000 at 10% simple interest for 8 years.

(6) Find the amount to be paid if Joseph borrowed a sum of $5700 at 10% simple interest for 7 years.

(7) Calculate the amount due if Linda borrowed a sum of $3350 at 4% simple interest for 4 years.

(8) Karen took a loan of $5900 at the rate of 10% simple interest per annum. If he paid an amount of $10620 to clear the loan, then find the time period of the loan.

(9) Calculate the amount due after 9 years if David borrowed a sum of $5400 at a rate of 10% simple interest.

(10) Find the amount to be paid if Jennifer borrowed a sum of $5250 at 8% simple interest for 7 years.