Simple Interest
MCQs Math


Question:     Calculate the amount due if Jennifer borrowed a sum of $3250 at 10% simple interest for 3 years.


Correct Answer  $4225

Solution And Explanation

Solution

Given,

Principal (P) = $3250

Rate of Simple Interest (SI) = 10%

Time (t) = 3 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) = $3250 × 10% × 3

= $3250 ×10/100 × 3

= 3250 × 10 × 3/100

= 32500 × 3/100

= 97500/100

= $975

Thus, Simple Interest = $975

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 = $3250 + $975

= $4225

Thus, Amount to be paid = $4225 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 = $3250

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

And, Time (t) = 3 years

Thus, Amount (A)

= $3250 + ($3250 × 10% × 3)

= $3250 + ($3250 ×10/100 × 3)

= $3250 + (3250 × 10 × 3/100)

= $3250 + (32500 × 3/100)

= $3250 + (97500/100)

= $3250 + $975 = $4225

Thus, Amount (A) to be paid = $4225 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 $3250, the simple interest in 1 year

= 10/100 × 3250

= 10 × 3250/100

= 32500/100 = $325

Thus, simple interest for 1 year = $325

Therefore, simple interest for 3 years

= Simple interest for 1 year × 3

= $325 × 3 = $975

Thus, Simple Interest (SI) = $975

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3250 + $975

= $4225

Thus, Amount to be paid = $4225 Answer


Similar Questions

(1) Find the amount to be paid if Richard borrowed a sum of $5600 at 5% simple interest for 7 years.

(2) How much loan did Melissa borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $9187.5 to clear it?

(3) Calculate the amount due if Richard borrowed a sum of $3600 at 10% simple interest for 4 years.

(4) Kenneth had to pay $5750 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(5) What amount will be due after 2 years if William borrowed a sum of $3250 at a 7% simple interest?

(6) William took a loan of $5000 at the rate of 10% simple interest per annum. If he paid an amount of $8000 to clear the loan, then find the time period of the loan.

(7) Calculate the amount due after 10 years if David borrowed a sum of $5400 at a rate of 10% simple interest.

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

(9) David had to pay $3910 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(10) If Patricia paid $3654 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.


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