Simple Interest
MCQs Math


Question:     Find the amount to be paid if Elizabeth borrowed a sum of $5450 at 6% simple interest for 8 years.


Correct Answer  $8066

Solution And Explanation

Solution

Given,

Principal (P) = $5450

Rate of Simple Interest (SI) = 6%

Time (t) = 8 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) = $5450 × 6% × 8

= $5450 ×6/100 × 8

= 5450 × 6 × 8/100

= 32700 × 8/100

= 261600/100

= $2616

Thus, Simple Interest = $2616

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 = $5450 + $2616

= $8066

Thus, Amount to be paid = $8066 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 = $5450

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

And, Time (t) = 8 years

Thus, Amount (A)

= $5450 + ($5450 × 6% × 8)

= $5450 + ($5450 ×6/100 × 8)

= $5450 + (5450 × 6 × 8/100)

= $5450 + (32700 × 8/100)

= $5450 + (261600/100)

= $5450 + $2616 = $8066

Thus, Amount (A) to be paid = $8066 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 $5450, the simple interest in 1 year

= 6/100 × 5450

= 6 × 5450/100

= 32700/100 = $327

Thus, simple interest for 1 year = $327

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $327 × 8 = $2616

Thus, Simple Interest (SI) = $2616

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5450 + $2616

= $8066

Thus, Amount to be paid = $8066 Answer


Similar Questions

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

(2) Calculate the amount due after 10 years if Barbara borrowed a sum of $5550 at a rate of 7% simple interest.

(3) Joseph took a loan of $5400 at the rate of 7% simple interest per annum. If he paid an amount of $8046 to clear the loan, then find the time period of the loan.

(4) Find the amount to be paid if Karen borrowed a sum of $5950 at 8% simple interest for 8 years.

(5) Michelle had to pay $5692.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(6) Calculate the amount due if William borrowed a sum of $3500 at 10% simple interest for 3 years.

(7) What amount does Richard have to pay after 6 years if he takes a loan of $3600 at 4% simple interest?

(8) Calculate the amount due after 10 years if Christopher borrowed a sum of $6000 at a rate of 4% simple interest.

(9) Mark took a loan of $6800 at the rate of 7% simple interest per annum. If he paid an amount of $11084 to clear the loan, then find the time period of the loan.

(10) Sarah took a loan of $5700 at the rate of 8% simple interest per annum. If he paid an amount of $8892 to clear the loan, then find the time period of the loan.


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