Simple Interest
MCQs Math


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


Correct Answer  $6758

Solution And Explanation

Solution

Given,

Principal (P) = $5450

Rate of Simple Interest (SI) = 3%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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 × 3% × 8

= $5450 ×3/100 × 8

= 5450 × 3 × 8/100

= 16350 × 8/100

= 130800/100

= $1308

Thus, Simple Interest = $1308

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 + $1308

= $6758

Thus, Amount to be paid = $6758 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) = 3%

And, Time (t) = 8 years

Thus, Amount (A)

= $5450 + ($5450 × 3% × 8)

= $5450 + ($5450 ×3/100 × 8)

= $5450 + (5450 × 3 × 8/100)

= $5450 + (16350 × 8/100)

= $5450 + (130800/100)

= $5450 + $1308 = $6758

Thus, Amount (A) to be paid = $6758 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = 3/100

∴ For $5450, the simple interest in 1 year

= 3/100 × 5450

= 3 × 5450/100

= 16350/100 = $163.5

Thus, simple interest for 1 year = $163.5

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $163.5 × 8 = $1308

Thus, Simple Interest (SI) = $1308

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5450 + $1308

= $6758

Thus, Amount to be paid = $6758 Answer


Similar Questions

(1) Calculate the amount due after 10 years if Richard borrowed a sum of $5600 at a rate of 8% simple interest.

(2) If Susan paid $3942 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.

(3) Calculate the amount due if Thomas borrowed a sum of $3800 at 7% simple interest for 4 years.

(4) Jennifer took a loan of $4500 at the rate of 8% simple interest per annum. If he paid an amount of $7740 to clear the loan, then find the time period of the loan.

(5) What amount does Thomas have to pay after 5 years if he takes a loan of $3800 at 6% simple interest?

(6) Find the amount to be paid if David borrowed a sum of $5400 at 8% simple interest for 7 years.

(7) Find the amount to be paid if David borrowed a sum of $5400 at 3% simple interest for 8 years.

(8) Calculate the amount due after 10 years if James borrowed a sum of $5000 at a rate of 9% simple interest.

(9) Richard took a loan of $5200 at the rate of 6% simple interest per annum. If he paid an amount of $7696 to clear the loan, then find the time period of the loan.

(10) In how much time a principal of $3050 will amount to $3233 at a simple interest of 2% per annum?


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