Simple Interest
MCQs Math


Question:     Find the amount to be paid if William borrowed a sum of $5500 at 9% simple interest for 8 years.


Correct Answer  $9460

Solution And Explanation

Solution

Given,

Principal (P) = $5500

Rate of Simple Interest (SI) = 9%

Time (t) = 8 years

Thus, Amount (A) = ?

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

Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% 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) = $5500 × 9% × 8

= $5500 ×9/100 × 8

= 5500 × 9 × 8/100

= 49500 × 8/100

= 396000/100

= $3960

Thus, Simple Interest = $3960

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 = $5500 + $3960

= $9460

Thus, Amount to be paid = $9460 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 = $5500

Rate of Simple Interest (SI) or (R) = 9%

And, Time (t) = 8 years

Thus, Amount (A)

= $5500 + ($5500 × 9% × 8)

= $5500 + ($5500 ×9/100 × 8)

= $5500 + (5500 × 9 × 8/100)

= $5500 + (49500 × 8/100)

= $5500 + (396000/100)

= $5500 + $3960 = $9460

Thus, Amount (A) to be paid = $9460 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 9%

This, means, $9 per $100 per year

∵ For $100, the simple interest for 1 year = $9

∴ For $1, the simple interest for 1 year = 9/100

∴ For $5500, the simple interest in 1 year

= 9/100 × 5500

= 9 × 5500/100

= 49500/100 = $495

Thus, simple interest for 1 year = $495

Therefore, simple interest for 8 years

= Simple interest for 1 year × 8

= $495 × 8 = $3960

Thus, Simple Interest (SI) = $3960

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5500 + $3960

= $9460

Thus, Amount to be paid = $9460 Answer


Similar Questions

(1) What amount does David have to pay after 6 years if he takes a loan of $3400 at 4% simple interest?

(2) David took a loan of $4800 at the rate of 9% simple interest per annum. If he paid an amount of $8256 to clear the loan, then find the time period of the loan.

(3) Find the amount to be paid if Mary borrowed a sum of $5050 at 8% simple interest for 8 years.

(4) Margaret took a loan of $6700 at the rate of 7% simple interest per annum. If he paid an amount of $9514 to clear the loan, then find the time period of the loan.

(5) Michael had to pay $3597 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(6) If Elizabeth borrowed $3450 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(7) Calculate the amount due after 10 years if Michael borrowed a sum of $5300 at a rate of 5% simple interest.

(8) If Margaret paid $4872 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(9) Calculate the amount due if Susan borrowed a sum of $3650 at 10% simple interest for 4 years.

(10) Joshua had to pay $5194 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.


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