Simple Interest
MCQs Math


Question:     Find the amount to be paid if John borrowed a sum of $5200 at 8% simple interest for 8 years.


Correct Answer  $8528

Solution And Explanation

Solution

Given,

Principal (P) = $5200

Rate of Simple Interest (SI) = 8%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 8% simple interest means, Rate of Simple Interest (SI) is 8% 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) = $5200 × 8% × 8

= $5200 ×8/100 × 8

= 5200 × 8 × 8/100

= 41600 × 8/100

= 332800/100

= $3328

Thus, Simple Interest = $3328

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 = $5200 + $3328

= $8528

Thus, Amount to be paid = $8528 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 = $5200

Rate of Simple Interest (SI) or (R) = 8%

And, Time (t) = 8 years

Thus, Amount (A)

= $5200 + ($5200 × 8% × 8)

= $5200 + ($5200 ×8/100 × 8)

= $5200 + (5200 × 8 × 8/100)

= $5200 + (41600 × 8/100)

= $5200 + (332800/100)

= $5200 + $3328 = $8528

Thus, Amount (A) to be paid = $8528 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 8%

This, means, $8 per $100 per year

∵ For $100, the simple interest for 1 year = $8

∴ For $1, the simple interest for 1 year = 8/100

∴ For $5200, the simple interest in 1 year

= 8/100 × 5200

= 8 × 5200/100

= 41600/100 = $416

Thus, simple interest for 1 year = $416

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $416 × 8 = $3328

Thus, Simple Interest (SI) = $3328

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5200 + $3328

= $8528

Thus, Amount to be paid = $8528 Answer


Similar Questions

(1) Matthew took a loan of $6400 at the rate of 9% simple interest per annum. If he paid an amount of $11584 to clear the loan, then find the time period of the loan.

(2) Calculate the amount due if Karen borrowed a sum of $3950 at 4% simple interest for 3 years.

(3) Patricia took a loan of $4300 at the rate of 7% simple interest per annum. If he paid an amount of $7310 to clear the loan, then find the time period of the loan.

(4) Calculate the amount due after 9 years if Jessica borrowed a sum of $5750 at a rate of 3% simple interest.

(5) Matthew took a loan of $6400 at the rate of 8% simple interest per annum. If he paid an amount of $10496 to clear the loan, then find the time period of the loan.

(6) Robert took a loan of $4200 at the rate of 9% simple interest per annum. If he paid an amount of $7224 to clear the loan, then find the time period of the loan.

(7) Karen took a loan of $5900 at the rate of 6% simple interest per annum. If he paid an amount of $8732 to clear the loan, then find the time period of the loan.

(8) Find the amount to be paid if Barbara borrowed a sum of $5550 at 5% simple interest for 8 years.

(9) Calculate the amount due after 9 years if William borrowed a sum of $5500 at a rate of 10% simple interest.

(10) Find the amount to be paid if Michael borrowed a sum of $5300 at 2% simple interest for 8 years.


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