Simple Interest
Math MCQs

Question :    Find the amount to be paid if Patricia borrowed a sum of $5150 at 4% simple interest for 7 years.

Correct Answer  $6592

Solution & Explanation

Solution

Given,

Principal (P) = $5150

Rate of Simple Interest (SI) = 4%

Time (t) = 7 years

Thus, Amount (A) = ?

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

Thus, here 4% simple interest means, Rate of Simple Interest (SI) is 4% 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 × 4% × 7

= $5150 ×⁴/₁₀₀ × 7

= ^{5150 × 4 × 7}/₁₀₀

= ^{20600 × 7}/₁₀₀

= ¹⁴⁴²⁰⁰/₁₀₀

= $1442

Thus, Simple Interest = $1442

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 + $1442

= $6592

Thus, Amount to be paid = $6592 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) = 4%

And, Time (t) = 7 years

Thus, Amount (A)

= $5150 + ($5150 × 4% × 7)

= $5150 + ($5150 ×⁴/₁₀₀ × 7)

= $5150 + (^{5150 × 4 × 7}/₁₀₀)

= $5150 + (^{20600 × 7}/₁₀₀)

= $5150 + (¹⁴⁴²⁰⁰/₁₀₀)

= $5150 + $1442 = $6592

Thus, Amount (A) to be paid = $6592 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 4%

This, means, $4 per $100 per year

∵ For $100, the simple interest for 1 year = $4

∴ For $1, the simple interest for 1 year = ⁴/₁₀₀

∴ For $5150, the simple interest in 1 year

= ⁴/₁₀₀ × 5150

= ^{4 × 5150}/₁₀₀

= ²⁰⁶⁰⁰/₁₀₀ = $206

Thus, simple interest for 1 year = $206

Therefore, simple interest for 7 years

= Simple interest for 1 year × 7

= $206 × 7 = $1442

Thus, Simple Interest (SI) = $1442

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5150 + $1442

= $6592

Thus, Amount to be paid = $6592 Answer

Similar Questions

(1) Mark took a loan of $6800 at the rate of 8% simple interest per annum. If he paid an amount of $10064 to clear the loan, then find the time period of the loan.

(2) What amount does Richard have to pay after 5 years if he takes a loan of $3600 at 10% simple interest?

(3) What amount does Barbara have to pay after 5 years if he takes a loan of $3550 at 10% simple interest?

(4) What amount does Susan have to pay after 5 years if he takes a loan of $3650 at 10% simple interest?

(5) Find the amount to be paid if Robert borrowed a sum of $5100 at 2% simple interest for 8 years.

(6) Jennifer took a loan of $4500 at the rate of 9% simple interest per annum. If he paid an amount of $8550 to clear the loan, then find the time period of the loan.

(7) Find the amount to be paid if Karen borrowed a sum of $5950 at 5% simple interest for 8 years.

(8) Calculate the amount due after 10 years if Charles borrowed a sum of $5900 at a rate of 7% simple interest.

(9) What amount does Joseph have to pay after 5 years if he takes a loan of $3700 at 10% simple interest?

(10) James took a loan of $4000 at the rate of 10% simple interest per annum. If he paid an amount of $6800 to clear the loan, then find the time period of the loan.