Simple Interest
MCQs Math


Question:     Calculate the amount due if Linda borrowed a sum of $3350 at 9% simple interest for 3 years.


Correct Answer  $4254.5

Solution And Explanation

Solution

Given,

Principal (P) = $3350

Rate of Simple Interest (SI) = 9%

Time (t) = 3 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) = $3350 × 9% × 3

= $3350 ×9/100 × 3

= 3350 × 9 × 3/100

= 30150 × 3/100

= 90450/100

= $904.5

Thus, Simple Interest = $904.5

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 = $3350 + $904.5

= $4254.5

Thus, Amount to be paid = $4254.5 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 = $3350

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

And, Time (t) = 3 years

Thus, Amount (A)

= $3350 + ($3350 × 9% × 3)

= $3350 + ($3350 ×9/100 × 3)

= $3350 + (3350 × 9 × 3/100)

= $3350 + (30150 × 3/100)

= $3350 + (90450/100)

= $3350 + $904.5 = $4254.5

Thus, Amount (A) to be paid = $4254.5 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 $3350, the simple interest in 1 year

= 9/100 × 3350

= 9 × 3350/100

= 30150/100 = $301.5

Thus, simple interest for 1 year = $301.5

Therefore, simple interest for 3 years

= Simple interest for 1 year × 3

= $301.5 × 3 = $904.5

Thus, Simple Interest (SI) = $904.5

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $3350 + $904.5

= $4254.5

Thus, Amount to be paid = $4254.5 Answer


Similar Questions

(1) Calculate the amount due if Joseph borrowed a sum of $3700 at 8% simple interest for 4 years.

(2) Lisa took a loan of $6100 at the rate of 7% simple interest per annum. If he paid an amount of $9089 to clear the loan, then find the time period of the loan.

(3) Calculate the amount due after 10 years if Susan borrowed a sum of $5650 at a rate of 9% simple interest.

(4) In how much time a principal of $3200 will amount to $3456 at a simple interest of 4% per annum?

(5) Elizabeth took a loan of $4900 at the rate of 9% simple interest per annum. If he paid an amount of $7987 to clear the loan, then find the time period of the loan.

(6) Calculate the amount due if Elizabeth borrowed a sum of $3450 at 5% simple interest for 4 years.

(7) In how much time a principal of $3150 will amount to $3622.5 at a simple interest of 3% per annum?

(8) If Michael borrowed $3300 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.

(9) Calculate the amount due if Jessica borrowed a sum of $3750 at 8% simple interest for 4 years.

(10) What amount will be due after 2 years if Anthony borrowed a sum of $3650 at a 7% simple interest?


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