Simple Interest
MCQs Math


Question:   ( 1 of 10 )  Find the amount to be paid if David borrowed a sum of $5400 at 10% simple interest for 7 years.

(A)  59
(B)  30.5
(C)  61
(D)  60

You selected   $5400

Correct Answer  $9180

Solution And Explanation

Solution

Given,

Principal (P) = $5400

Rate of Simple Interest (SI) = 10%

Time (t) = 7 years

Thus, Amount (A) = ?

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

Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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) = $5400 × 10% × 7

= $5400 ×10/100 × 7

= 5400 × 10 × 7/100

= 54000 × 7/100

= 378000/100

= $3780

Thus, Simple Interest = $3780

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 = $5400 + $3780

= $9180

Thus, Amount to be paid = $9180 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 = $5400

Rate of Simple Interest (SI) or (R) = 10%

And, Time (t) = 7 years

Thus, Amount (A)

= $5400 + ($5400 × 10% × 7)

= $5400 + ($5400 ×10/100 × 7)

= $5400 + (5400 × 10 × 7/100)

= $5400 + (54000 × 7/100)

= $5400 + (378000/100)

= $5400 + $3780 = $9180

Thus, Amount (A) to be paid = $9180 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 10%

This, means, $10 per $100 per year

∵ For $100, the simple interest for 1 year = $10

∴ For $1, the simple interest for 1 year = 10/100

∴ For $5400, the simple interest in 1 year

= 10/100 × 5400

= 10 × 5400/100

= 54000/100 = $540

Thus, simple interest for 1 year = $540

Therefore, simple interest for 7 years

= Simple interest for 1 year × 7

= $540 × 7 = $3780

Thus, Simple Interest (SI) = $3780

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5400 + $3780

= $9180

Thus, Amount to be paid = $9180 Answer


Similar Questions

(1) Karen took a loan of $5900 at the rate of 6% simple interest per annum. If he paid an amount of $9440 to clear the loan, then find the time period of the loan.

(2) Paul had to pay $4982 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(3) What amount will be due after 2 years if David borrowed a sum of $3200 at a 7% simple interest?

(4) Calculate the amount due after 9 years if Michael borrowed a sum of $5300 at a rate of 7% simple interest.

(5) What amount does Sarah have to pay after 5 years if he takes a loan of $3850 at 5% simple interest?

(6) Calculate the amount due after 10 years if Robert borrowed a sum of $5100 at a rate of 8% simple interest.

(7) David took a loan of $4800 at the rate of 7% simple interest per annum. If he paid an amount of $7824 to clear the loan, then find the time period of the loan.

(8) In how much time a principal of $3000 will amount to $3120 at a simple interest of 2% per annum?

(9) What amount does David have to pay after 5 years if he takes a loan of $3400 at 9% simple interest?

(10) Calculate the amount due if Jessica borrowed a sum of $3750 at 7% simple interest for 3 years.


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