Simple Interest
MCQs Math


Question:     Calculate the amount due if Michael borrowed a sum of $3300 at 8% simple interest for 3 years.


Correct Answer  $4092

Solution And Explanation

Solution

Given,

Principal (P) = $3300

Rate of Simple Interest (SI) = 8%

Time (t) = 3 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) = $3300 × 8% × 3

= $3300 ×8/100 × 3

= 3300 × 8 × 3/100

= 26400 × 3/100

= 79200/100

= $792

Thus, Simple Interest = $792

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 + $792

= $4092

Thus, Amount to be paid = $4092 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) = 8%

And, Time (t) = 3 years

Thus, Amount (A)

= $3300 + ($3300 × 8% × 3)

= $3300 + ($3300 ×8/100 × 3)

= $3300 + (3300 × 8 × 3/100)

= $3300 + (26400 × 3/100)

= $3300 + (79200/100)

= $3300 + $792 = $4092

Thus, Amount (A) to be paid = $4092 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 $3300, the simple interest in 1 year

= 8/100 × 3300

= 8 × 3300/100

= 26400/100 = $264

Thus, simple interest for 1 year = $264

Therefore, simple interest for 3 years

= Simple interest for 1 year × 3

= $264 × 3 = $792

Thus, Simple Interest (SI) = $792

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3300 + $792

= $4092

Thus, Amount to be paid = $4092 Answer


Similar Questions

(1) Find the amount to be paid if Barbara borrowed a sum of $5550 at 6% simple interest for 7 years.

(2) What amount does Richard have to pay after 5 years if he takes a loan of $3600 at 8% simple interest?

(3) What amount will be due after 2 years if Paul borrowed a sum of $3850 at a 5% simple interest?

(4) Robert took a loan of $4200 at the rate of 9% simple interest per annum. If he paid an amount of $6468 to clear the loan, then find the time period of the loan.

(5) Find the amount to be paid if Thomas borrowed a sum of $5800 at 6% simple interest for 7 years.

(6) If Elizabeth paid $4002 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.

(7) How much loan did Linda borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $6687.5 to clear it?

(8) Find the amount to be paid if Sarah borrowed a sum of $5850 at 6% simple interest for 8 years.

(9) Calculate the amount due after 9 years if Sarah borrowed a sum of $5850 at a rate of 3% simple interest.

(10) Calculate the amount due after 10 years if James borrowed a sum of $5000 at a rate of 4% simple interest.


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