Simple Interest
MCQs Math


Question:     What amount does Michael have to pay after 6 years if he takes a loan of $3300 at 9% simple interest?


Correct Answer  $5082

Solution And Explanation

Solution

Given,

Principal (P) = $3300

Rate of Simple Interest (SI) = 9%

Time (t) = 6 years

Thus, Amount (A) = ?

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

Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% 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) = $3300 × 9% × 6

= $3300 ×9/100 × 6

= 3300 × 9 × 6/100

= 29700 × 6/100

= 178200/100

= $1782

Thus, Simple Interest = $1782

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 = $3300 + $1782

= $5082

Thus, Amount to be paid = $5082 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 = $3300

Rate of Simple Interest (SI) or (R) = 9%

And, Time (t) = 6 years

Thus, Amount (A)

= $3300 + ($3300 × 9% × 6)

= $3300 + ($3300 ×9/100 × 6)

= $3300 + (3300 × 9 × 6/100)

= $3300 + (29700 × 6/100)

= $3300 + (178200/100)

= $3300 + $1782 = $5082

Thus, Amount (A) to be paid = $5082 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 9%

This, means, $9 per $100 per year

∵ For $100, the simple interest for 1 year = $9

∴ For $1, the simple interest for 1 year = 9/100

∴ For $3300, the simple interest in 1 year

= 9/100 × 3300

= 9 × 3300/100

= 29700/100 = $297

Thus, simple interest for 1 year = $297

Therefore, simple interest for 6 years

= Simple interest for 1 year × 6

= $297 × 6 = $1782

Thus, Simple Interest (SI) = $1782

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3300 + $1782

= $5082

Thus, Amount to be paid = $5082 Answer


Similar Questions

(1) Calculate the amount due if Barbara borrowed a sum of $3550 at 5% simple interest for 4 years.

(2) Calculate the amount due if Linda borrowed a sum of $3350 at 10% simple interest for 3 years.

(3) In how much time a principal of $3100 will amount to $3472 at a simple interest of 4% per annum?

(4) Calculate the amount due if Thomas borrowed a sum of $3800 at 9% simple interest for 3 years.

(5) Calculate the amount due after 10 years if Elizabeth borrowed a sum of $5450 at a rate of 6% simple interest.

(6) Jessica took a loan of $5500 at the rate of 7% simple interest per annum. If he paid an amount of $9350 to clear the loan, then find the time period of the loan.

(7) In how much time a principal of $3050 will amount to $3538 at a simple interest of 4% per annum?

(8) Susan took a loan of $5300 at the rate of 6% simple interest per annum. If he paid an amount of $8162 to clear the loan, then find the time period of the loan.

(9) Matthew took a loan of $6400 at the rate of 6% simple interest per annum. If he paid an amount of $9856 to clear the loan, then find the time period of the loan.

(10) Find the amount to be paid if Robert borrowed a sum of $5100 at 8% simple interest for 7 years.


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