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) Find the amount to be paid if Robert borrowed a sum of $5100 at 10% simple interest for 7 years.

(2) Calculate the amount due if Jessica borrowed a sum of $3750 at 6% simple interest for 3 years.

(3) Matthew took a loan of $6400 at the rate of 6% simple interest per annum. If he paid an amount of $9088 to clear the loan, then find the time period of the loan.

(4) What amount does Robert have to pay after 5 years if he takes a loan of $3100 at 7% simple interest?

(5) Find the amount to be paid if Thomas borrowed a sum of $5800 at 9% simple interest for 7 years.

(6) If David borrowed $3400 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(7) Find the amount to be paid if Charles borrowed a sum of $5900 at 2% simple interest for 8 years.

(8) Matthew had to pay $4578 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(9) Susan took a loan of $5300 at the rate of 8% simple interest per annum. If he paid an amount of $8692 to clear the loan, then find the time period of the loan.

(10) How much loan did Andrew borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7820 to clear it?


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