Simple Interest
MCQs Math


Question:   ( 1 of 10 )  Calculate the amount due after 9 years if Robert borrowed a sum of $5100 at a rate of 5% simple interest.

(A)  59
(B)  30.5
(C)  61
(D)  60

You selected   $5100

Correct Answer  $7395

Solution And Explanation

Solution

Given,

Principal (P) = $5100

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) = $5100 × 5% × 9

= $5100 ×5/100 × 9

= 5100 × 5 × 9/100

= 25500 × 9/100

= 229500/100

= $2295

Thus, Simple Interest = $2295

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 = $5100 + $2295

= $7395

Thus, Amount to be paid = $7395 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 = $5100

Rate of Simple Interest (SI) or (R) = 5%

And, Time (t) = 9 years

Thus, Amount (A)

= $5100 + ($5100 × 5% × 9)

= $5100 + ($5100 ×5/100 × 9)

= $5100 + (5100 × 5 × 9/100)

= $5100 + (25500 × 9/100)

= $5100 + (229500/100)

= $5100 + $2295 = $7395

Thus, Amount (A) to be paid = $7395 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 $5100, the simple interest in 1 year

= 5/100 × 5100

= 5 × 5100/100

= 25500/100 = $255

Thus, simple interest for 1 year = $255

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $255 × 9 = $2295

Thus, Simple Interest (SI) = $2295

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5100 + $2295

= $7395

Thus, Amount to be paid = $7395 Answer


Similar Questions

(1) Calculate the amount due if Barbara borrowed a sum of $3550 at 9% simple interest for 4 years.

(2) Mary took a loan of $4100 at the rate of 6% simple interest per annum. If he paid an amount of $5822 to clear the loan, then find the time period of the loan.

(3) Karen took a loan of $5900 at the rate of 9% simple interest per annum. If he paid an amount of $9617 to clear the loan, then find the time period of the loan.

(4) Calculate the amount due if Elizabeth borrowed a sum of $3450 at 6% simple interest for 4 years.

(5) What amount will be due after 2 years if Steven borrowed a sum of $3800 at a 6% simple interest?

(6) Find the amount to be paid if Karen borrowed a sum of $5950 at 7% simple interest for 8 years.

(7) Linda took a loan of $4700 at the rate of 7% simple interest per annum. If he paid an amount of $6674 to clear the loan, then find the time period of the loan.

(8) James took a loan of $4000 at the rate of 6% simple interest per annum. If he paid an amount of $5440 to clear the loan, then find the time period of the loan.

(9) Christopher had to pay $4240 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(10) Jennifer took a loan of $4500 at the rate of 7% simple interest per annum. If he paid an amount of $7335 to clear the loan, then find the time period of the loan.


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