Simple Interest
MCQs Math


Question:     Find the amount to be paid if Elizabeth borrowed a sum of $5450 at 2% simple interest for 8 years.


Correct Answer  $6322

Solution And Explanation

Solution

Given,

Principal (P) = $5450

Rate of Simple Interest (SI) = 2%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 2% simple interest means, Rate of Simple Interest (SI) is 2% 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 × 2% × 8

= $5450 ×2/100 × 8

= 5450 × 2 × 8/100

= 10900 × 8/100

= 87200/100

= $872

Thus, Simple Interest = $872

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 + $872

= $6322

Thus, Amount to be paid = $6322 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) = 2%

And, Time (t) = 8 years

Thus, Amount (A)

= $5450 + ($5450 × 2% × 8)

= $5450 + ($5450 ×2/100 × 8)

= $5450 + (5450 × 2 × 8/100)

= $5450 + (10900 × 8/100)

= $5450 + (87200/100)

= $5450 + $872 = $6322

Thus, Amount (A) to be paid = $6322 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 2%

This, means, $2 per $100 per year

∵ For $100, the simple interest for 1 year = $2

∴ For $1, the simple interest for 1 year = 2/100

∴ For $5450, the simple interest in 1 year

= 2/100 × 5450

= 2 × 5450/100

= 10900/100 = $109

Thus, simple interest for 1 year = $109

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $109 × 8 = $872

Thus, Simple Interest (SI) = $872

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5450 + $872

= $6322

Thus, Amount to be paid = $6322 Answer


Similar Questions

(1) Elizabeth took a loan of $4900 at the rate of 10% simple interest per annum. If he paid an amount of $8820 to clear the loan, then find the time period of the loan.

(2) Calculate the amount due if Linda borrowed a sum of $3350 at 7% simple interest for 3 years.

(3) Matthew took a loan of $6400 at the rate of 9% simple interest per annum. If he paid an amount of $11008 to clear the loan, then find the time period of the loan.

(4) How much loan did Donald borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $7800 to clear it?

(5) Sandra took a loan of $6900 at the rate of 9% simple interest per annum. If he paid an amount of $12489 to clear the loan, then find the time period of the loan.

(6) Daniel took a loan of $6200 at the rate of 7% simple interest per annum. If he paid an amount of $8804 to clear the loan, then find the time period of the loan.

(7) What amount does William have to pay after 6 years if he takes a loan of $3500 at 10% simple interest?

(8) How much loan did William borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $6875 to clear it?

(9) John took a loan of $4400 at the rate of 8% simple interest per annum. If he paid an amount of $7216 to clear the loan, then find the time period of the loan.

(10) What amount does Patricia have to pay after 5 years if he takes a loan of $3150 at 2% simple interest?


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