Simple Interest
MCQs Math


Question:     What amount will be due after 2 years if Joshua borrowed a sum of $3950 at a 9% simple interest?


Correct Answer  $4661

Solution And Explanation

Solution

Given,

Principal (P) = $3950

Rate of Simple Interest (SI) = 9%

Time (t) = 2 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) = $3950 × 9% × 2

= $3950 ×9/100 × 2

= 3950 × 9 × 2/100

= 35550 × 2/100

= 71100/100

= $711

Thus, Simple Interest = $711

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 = $3950 + $711

= $4661

Thus, Amount to be paid = $4661 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 = $3950

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

And, Time (t) = 2 years

Thus, Amount (A)

= $3950 + ($3950 × 9% × 2)

= $3950 + ($3950 ×9/100 × 2)

= $3950 + (3950 × 9 × 2/100)

= $3950 + (35550 × 2/100)

= $3950 + (71100/100)

= $3950 + $711 = $4661

Thus, Amount (A) to be paid = $4661 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 $3950, the simple interest in 1 year

= 9/100 × 3950

= 9 × 3950/100

= 35550/100 = $355.5

Thus, simple interest for 1 year = $355.5

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $355.5 × 2 = $711

Thus, Simple Interest (SI) = $711

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3950 + $711

= $4661

Thus, Amount to be paid = $4661 Answer


Similar Questions

(1) If Richard paid $4032 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(2) Margaret took a loan of $6700 at the rate of 10% simple interest per annum. If he paid an amount of $12060 to clear the loan, then find the time period of the loan.

(3) Michael had to pay $3696 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(4) Christopher took a loan of $6000 at the rate of 8% simple interest per annum. If he paid an amount of $9840 to clear the loan, then find the time period of the loan.

(5) How much loan did Jacob borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $9200 to clear it?

(6) Barbara took a loan of $5100 at the rate of 8% simple interest per annum. If he paid an amount of $8364 to clear the loan, then find the time period of the loan.

(7) Paul had to pay $5405 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.

(8) In how much time a principal of $3050 will amount to $3538 at a simple interest of 4% per annum?

(9) Calculate the amount due if Jennifer borrowed a sum of $3250 at 2% simple interest for 4 years.

(10) Lisa took a loan of $6100 at the rate of 8% simple interest per annum. If he paid an amount of $9028 to clear the loan, then find the time period of the loan.


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