Simple Interest
MCQs Math


Question:     Find the amount to be paid if James borrowed a sum of $5000 at 9% simple interest for 8 years.


Correct Answer  $8600

Solution And Explanation

Solution

Given,

Principal (P) = $5000

Rate of Simple Interest (SI) = 9%

Time (t) = 8 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) = $5000 × 9% × 8

= $5000 ×9/100 × 8

= 5000 × 9 × 8/100

= 45000 × 8/100

= 360000/100

= $3600

Thus, Simple Interest = $3600

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 = $5000 + $3600

= $8600

Thus, Amount to be paid = $8600 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 = $5000

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

And, Time (t) = 8 years

Thus, Amount (A)

= $5000 + ($5000 × 9% × 8)

= $5000 + ($5000 ×9/100 × 8)

= $5000 + (5000 × 9 × 8/100)

= $5000 + (45000 × 8/100)

= $5000 + (360000/100)

= $5000 + $3600 = $8600

Thus, Amount (A) to be paid = $8600 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 $5000, the simple interest in 1 year

= 9/100 × 5000

= 9 × 5000/100

= 45000/100 = $450

Thus, simple interest for 1 year = $450

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $450 × 8 = $3600

Thus, Simple Interest (SI) = $3600

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5000 + $3600

= $8600

Thus, Amount to be paid = $8600 Answer


Similar Questions

(1) How much loan did Paul borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7705 to clear it?

(2) Calculate the amount due after 10 years if Jennifer borrowed a sum of $5250 at a rate of 4% simple interest.

(3) David took a loan of $4800 at the rate of 6% simple interest per annum. If he paid an amount of $7104 to clear the loan, then find the time period of the loan.

(4) Calculate the amount due after 10 years if Jennifer borrowed a sum of $5250 at a rate of 3% simple interest.

(5) Calculate the amount due after 10 years if Thomas borrowed a sum of $5800 at a rate of 6% simple interest.

(6) Calculate the amount due if Jennifer borrowed a sum of $3250 at 10% simple interest for 4 years.

(7) Daniel took a loan of $6200 at the rate of 8% simple interest per annum. If he paid an amount of $10168 to clear the loan, then find the time period of the loan.

(8) Calculate the amount due after 10 years if Barbara borrowed a sum of $5550 at a rate of 9% simple interest.

(9) Sarah took a loan of $5700 at the rate of 7% simple interest per annum. If he paid an amount of $8892 to clear the loan, then find the time period of the loan.

(10) What amount does Robert have to pay after 6 years if he takes a loan of $3100 at 8% simple interest?


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