Simple Interest
MCQs Math


Question:     Calculate the amount due after 9 years if William borrowed a sum of $5500 at a rate of 8% simple interest.


Correct Answer  $9460

Solution And Explanation

Solution

Given,

Principal (P) = $5500

Rate of Simple Interest (SI) = 8%

Time (t) = 9 years

Thus, Amount (A) = ?

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

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

= $5500 ×8/100 × 9

= 5500 × 8 × 9/100

= 44000 × 9/100

= 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) = 8%

And, Time (t) = 9 years

Thus, Amount (A)

= $5500 + ($5500 × 8% × 9)

= $5500 + ($5500 ×8/100 × 9)

= $5500 + (5500 × 8 × 9/100)

= $5500 + (44000 × 9/100)

= $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 = 8%

This, means, $8 per $100 per year

∵ For $100, the simple interest for 1 year = $8

∴ For $1, the simple interest for 1 year = 8/100

∴ For $5500, the simple interest in 1 year

= 8/100 × 5500

= 8 × 5500/100

= 44000/100 = $440

Thus, simple interest for 1 year = $440

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $440 × 9 = $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) Calculate the amount due after 10 years if Patricia borrowed a sum of $5150 at a rate of 10% simple interest.

(2) Calculate the amount due after 10 years if Christopher borrowed a sum of $6000 at a rate of 6% simple interest.

(3) What amount does John have to pay after 6 years if he takes a loan of $3200 at 3% simple interest?

(4) Jessica took a loan of $5500 at the rate of 6% simple interest per annum. If he paid an amount of $8800 to clear the loan, then find the time period of the loan.

(5) What amount does Patricia have to pay after 6 years if he takes a loan of $3150 at 8% simple interest?

(6) Calculate the amount due after 10 years if Linda borrowed a sum of $5350 at a rate of 3% simple interest.

(7) Calculate the amount due if Robert borrowed a sum of $3100 at 5% simple interest for 4 years.

(8) Calculate the amount due if Joseph borrowed a sum of $3700 at 8% simple interest for 4 years.

(9) Christopher had to pay $4600 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(10) Find the amount to be paid if Michael borrowed a sum of $5300 at 8% simple interest for 8 years.


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