Simple Interest
MCQs Math


Question:     Calculate the amount due after 9 years if Jennifer borrowed a sum of $5250 at a rate of 3% simple interest.


Correct Answer  $6667.5

Solution And Explanation

Solution

Given,

Principal (P) = $5250

Rate of Simple Interest (SI) = 3%

Time (t) = 9 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) = $5250 × 3% × 9

= $5250 ×3/100 × 9

= 5250 × 3 × 9/100

= 15750 × 9/100

= 141750/100

= $1417.5

Thus, Simple Interest = $1417.5

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 = $5250 + $1417.5

= $6667.5

Thus, Amount to be paid = $6667.5 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 = $5250

Rate of Simple Interest (SI) or (R) = 3%

And, Time (t) = 9 years

Thus, Amount (A)

= $5250 + ($5250 × 3% × 9)

= $5250 + ($5250 ×3/100 × 9)

= $5250 + (5250 × 3 × 9/100)

= $5250 + (15750 × 9/100)

= $5250 + (141750/100)

= $5250 + $1417.5 = $6667.5

Thus, Amount (A) to be paid = $6667.5 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 $5250, the simple interest in 1 year

= 3/100 × 5250

= 3 × 5250/100

= 15750/100 = $157.5

Thus, simple interest for 1 year = $157.5

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $157.5 × 9 = $1417.5

Thus, Simple Interest (SI) = $1417.5

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5250 + $1417.5

= $6667.5

Thus, Amount to be paid = $6667.5 Answer


Similar Questions

(1) Find the amount to be paid if Joseph borrowed a sum of $5700 at 4% simple interest for 8 years.

(2) David took a loan of $4800 at the rate of 7% simple interest per annum. If he paid an amount of $7488 to clear the loan, then find the time period of the loan.

(3) Calculate the amount due after 9 years if Joseph borrowed a sum of $5700 at a rate of 9% simple interest.

(4) Elizabeth had to pay $3657 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.

(5) Calculate the amount due after 9 years if David borrowed a sum of $5400 at a rate of 10% simple interest.

(6) Calculate the amount due after 10 years if Richard borrowed a sum of $5600 at a rate of 8% simple interest.

(7) Michael took a loan of $4600 at the rate of 9% simple interest per annum. If he paid an amount of $8740 to clear the loan, then find the time period of the loan.

(8) Calculate the amount due if Karen borrowed a sum of $3950 at 9% simple interest for 3 years.

(9) Margaret took a loan of $6700 at the rate of 9% simple interest per annum. If he paid an amount of $12730 to clear the loan, then find the time period of the loan.

(10) What amount does Robert have to pay after 6 years if he takes a loan of $3100 at 6% simple interest?


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