Simple Interest
MCQs Math


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


Correct Answer  $3542.5

Solution And Explanation

Solution

Given,

Principal (P) = $3250

Rate of Simple Interest (SI) = 3%

Time (t) = 3 years

Thus, Amount (A) = ?

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

Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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 × 3% × 3

= $3250 ×3/100 × 3

= 3250 × 3 × 3/100

= 9750 × 3/100

= 29250/100

= $292.5

Thus, Simple Interest = $292.5

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 + $292.5

= $3542.5

Thus, Amount to be paid = $3542.5 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) = 3%

And, Time (t) = 3 years

Thus, Amount (A)

= $3250 + ($3250 × 3% × 3)

= $3250 + ($3250 ×3/100 × 3)

= $3250 + (3250 × 3 × 3/100)

= $3250 + (9750 × 3/100)

= $3250 + (29250/100)

= $3250 + $292.5 = $3542.5

Thus, Amount (A) to be paid = $3542.5 Answer

Method (3) Unitary Method

Calculation of Amount using Unitary Method

Calculation of Interest using Unitary Method

Here, given Rate of Simple Interest = 3%

This, means, $3 per $100 per year

∵ For $100, the simple interest for 1 year = $3

∴ For $1, the simple interest for 1 year = 3/100

∴ For $3250, the simple interest in 1 year

= 3/100 × 3250

= 3 × 3250/100

= 9750/100 = $97.5

Thus, simple interest for 1 year = $97.5

Therefore, simple interest for 3 years

= Simple interest for 1 year × 3

= $97.5 × 3 = $292.5

Thus, Simple Interest (SI) = $292.5

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3250 + $292.5

= $3542.5

Thus, Amount to be paid = $3542.5 Answer


Similar Questions

(1) Sarah took a loan of $5700 at the rate of 10% simple interest per annum. If he paid an amount of $9120 to clear the loan, then find the time period of the loan.

(2) Find the amount to be paid if Robert borrowed a sum of $5100 at 8% simple interest for 7 years.

(3) James took a loan of $4000 at the rate of 8% simple interest per annum. If he paid an amount of $6240 to clear the loan, then find the time period of the loan.

(4) Calculate the amount due if Barbara borrowed a sum of $3550 at 4% simple interest for 3 years.

(5) Jennifer took a loan of $4500 at the rate of 7% simple interest per annum. If he paid an amount of $6705 to clear the loan, then find the time period of the loan.

(6) What amount does David have to pay after 5 years if he takes a loan of $3400 at 3% simple interest?

(7) What amount does Karen have to pay after 6 years if he takes a loan of $3950 at 3% simple interest?

(8) Calculate the amount due if Joseph borrowed a sum of $3700 at 9% simple interest for 3 years.

(9) What amount does James have to pay after 5 years if he takes a loan of $3000 at 5% simple interest?

(10) Joseph took a loan of $5400 at the rate of 10% simple interest per annum. If he paid an amount of $8640 to clear the loan, then find the time period of the loan.


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