Simple Interest
MCQs Math


Question:     Calculate the amount due after 9 years if Elizabeth borrowed a sum of $5450 at a rate of 5% simple interest.


Correct Answer  $7902.5

Solution And Explanation

Solution

Given,

Principal (P) = $5450

Rate of Simple Interest (SI) = 5%

Time (t) = 9 years

Thus, Amount (A) = ?

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

Thus, here 5% simple interest means, Rate of Simple Interest (SI) is 5% 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 × 5% × 9

= $5450 ×5/100 × 9

= 5450 × 5 × 9/100

= 27250 × 9/100

= 245250/100

= $2452.5

Thus, Simple Interest = $2452.5

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 + $2452.5

= $7902.5

Thus, Amount to be paid = $7902.5 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) = 5%

And, Time (t) = 9 years

Thus, Amount (A)

= $5450 + ($5450 × 5% × 9)

= $5450 + ($5450 ×5/100 × 9)

= $5450 + (5450 × 5 × 9/100)

= $5450 + (27250 × 9/100)

= $5450 + (245250/100)

= $5450 + $2452.5 = $7902.5

Thus, Amount (A) to be paid = $7902.5 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 5%

This, means, $5 per $100 per year

∵ For $100, the simple interest for 1 year = $5

∴ For $1, the simple interest for 1 year = 5/100

∴ For $5450, the simple interest in 1 year

= 5/100 × 5450

= 5 × 5450/100

= 27250/100 = $272.5

Thus, simple interest for 1 year = $272.5

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $272.5 × 9 = $2452.5

Thus, Simple Interest (SI) = $2452.5

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5450 + $2452.5

= $7902.5

Thus, Amount to be paid = $7902.5 Answer


Similar Questions

(1) Lisa took a loan of $6100 at the rate of 6% simple interest per annum. If he paid an amount of $9394 to clear the loan, then find the time period of the loan.

(2) Find the amount to be paid if William borrowed a sum of $5500 at 3% simple interest for 8 years.

(3) Find the amount to be paid if Elizabeth borrowed a sum of $5450 at 7% simple interest for 8 years.

(4) Calculate the amount due after 9 years if Karen borrowed a sum of $5950 at a rate of 6% simple interest.

(5) Susan took a loan of $5300 at the rate of 10% simple interest per annum. If he paid an amount of $10600 to clear the loan, then find the time period of the loan.

(6) What amount does James have to pay after 5 years if he takes a loan of $3000 at 9% simple interest?

(7) What amount will be due after 2 years if Paul borrowed a sum of $3850 at a 4% simple interest?

(8) Calculate the amount due if David borrowed a sum of $3400 at 7% simple interest for 4 years.

(9) Anthony took a loan of $6600 at the rate of 10% simple interest per annum. If he paid an amount of $10560 to clear the loan, then find the time period of the loan.

(10) If James paid $3240 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.


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