Simple Interest
Math MCQs

Question :    Find the amount to be paid if Jennifer borrowed a sum of $5250 at 6% simple interest for 7 years.

Correct Answer  $7455

Solution & Explanation

Solution

Given,

Principal (P) = $5250

Rate of Simple Interest (SI) = 6%

Time (t) = 7 years

Thus, Amount (A) = ?

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

Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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) = $5250 × 6% × 7

= $5250 ×⁶/₁₀₀ × 7

= ^{5250 × 6 × 7}/₁₀₀

= ^{31500 × 7}/₁₀₀

= ²²⁰⁵⁰⁰/₁₀₀

= $2205

Thus, Simple Interest = $2205

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 = $5250 + $2205

= $7455

Thus, Amount to be paid = $7455 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 = $5250

Rate of Simple Interest (SI) or (R) = 6%

And, Time (t) = 7 years

Thus, Amount (A)

= $5250 + ($5250 × 6% × 7)

= $5250 + ($5250 ×⁶/₁₀₀ × 7)

= $5250 + (^{5250 × 6 × 7}/₁₀₀)

= $5250 + (^{31500 × 7}/₁₀₀)

= $5250 + (²²⁰⁵⁰⁰/₁₀₀)

= $5250 + $2205 = $7455

Thus, Amount (A) to be paid = $7455 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 6%

This, means, $6 per $100 per year

∵ For $100, the simple interest for 1 year = $6

∴ For $1, the simple interest for 1 year = ⁶/₁₀₀

∴ For $5250, the simple interest in 1 year

= ⁶/₁₀₀ × 5250

= ^{6 × 5250}/₁₀₀

= ³¹⁵⁰⁰/₁₀₀ = $315

Thus, simple interest for 1 year = $315

Therefore, simple interest for 7 years

= Simple interest for 1 year × 7

= $315 × 7 = $2205

Thus, Simple Interest (SI) = $2205

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5250 + $2205

= $7455

Thus, Amount to be paid = $7455 Answer

Similar Questions

(1) Anthony took a loan of $6600 at the rate of 10% simple interest per annum. If he paid an amount of $13200 to clear the loan, then find the time period of the loan.

(2) How much loan did Matthew borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $6820 to clear it?

(3) Find the amount to be paid if Sarah borrowed a sum of $5850 at 2% simple interest for 8 years.

(4) Find the amount to be paid if Sarah borrowed a sum of $5850 at 9% simple interest for 8 years.

(5) Karen took a loan of $5900 at the rate of 7% simple interest per annum. If he paid an amount of $8378 to clear the loan, then find the time period of the loan.

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

(7) How much loan did Jennifer borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $5775 to clear it?

(8) What amount will be due after 2 years if Robert borrowed a sum of $3050 at a 10% simple interest?

(9) If James paid $3240 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(10) What amount does Mary have to pay after 5 years if he takes a loan of $3050 at 4% simple interest?