Simple Interest
MCQs Math


Question:     What amount will be due after 2 years if Paul borrowed a sum of $3850 at a 9% simple interest?


Correct Answer  $4543

Solution And Explanation

Solution

Given,

Principal (P) = $3850

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) = $3850 × 9% × 2

= $3850 ×9/100 × 2

= 3850 × 9 × 2/100

= 34650 × 2/100

= 69300/100

= $693

Thus, Simple Interest = $693

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 = $3850 + $693

= $4543

Thus, Amount to be paid = $4543 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 = $3850

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

And, Time (t) = 2 years

Thus, Amount (A)

= $3850 + ($3850 × 9% × 2)

= $3850 + ($3850 ×9/100 × 2)

= $3850 + (3850 × 9 × 2/100)

= $3850 + (34650 × 2/100)

= $3850 + (69300/100)

= $3850 + $693 = $4543

Thus, Amount (A) to be paid = $4543 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 $3850, the simple interest in 1 year

= 9/100 × 3850

= 9 × 3850/100

= 34650/100 = $346.5

Thus, simple interest for 1 year = $346.5

Therefore, simple interest for 2 years

= Simple interest for 1 year × 2

= $346.5 × 2 = $693

Thus, Simple Interest (SI) = $693

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3850 + $693

= $4543

Thus, Amount to be paid = $4543 Answer


Similar Questions

(1) What amount does Joseph have to pay after 6 years if he takes a loan of $3700 at 7% simple interest?

(2) Richard had to pay $4032 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.

(3) Calculate the amount due after 10 years if Robert borrowed a sum of $5100 at a rate of 9% simple interest.

(4) What amount will be due after 2 years if Christopher borrowed a sum of $3500 at a 4% simple interest?

(5) Christopher took a loan of $6000 at the rate of 8% simple interest per annum. If he paid an amount of $9360 to clear the loan, then find the time period of the loan.

(6) David took a loan of $4800 at the rate of 9% simple interest per annum. If he paid an amount of $8688 to clear the loan, then find the time period of the loan.

(7) David took a loan of $4800 at the rate of 8% simple interest per annum. If he paid an amount of $8256 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 6% simple interest for 4 years.

(9) How much loan did David borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $6210 to clear it?

(10) Nancy took a loan of $6300 at the rate of 9% simple interest per annum. If he paid an amount of $10836 to clear the loan, then find the time period of the loan.


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