Simple Interest
MCQs Math


Question:     Calculate the amount due after 9 years if Barbara borrowed a sum of $5550 at a rate of 3% simple interest.


Correct Answer  $7048.5

Solution And Explanation

Solution

Given,

Principal (P) = $5550

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) = $5550 × 3% × 9

= $5550 ×3/100 × 9

= 5550 × 3 × 9/100

= 16650 × 9/100

= 149850/100

= $1498.5

Thus, Simple Interest = $1498.5

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 = $5550 + $1498.5

= $7048.5

Thus, Amount to be paid = $7048.5 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 = $5550

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

And, Time (t) = 9 years

Thus, Amount (A)

= $5550 + ($5550 × 3% × 9)

= $5550 + ($5550 ×3/100 × 9)

= $5550 + (5550 × 3 × 9/100)

= $5550 + (16650 × 9/100)

= $5550 + (149850/100)

= $5550 + $1498.5 = $7048.5

Thus, Amount (A) to be paid = $7048.5 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 $5550, the simple interest in 1 year

= 3/100 × 5550

= 3 × 5550/100

= 16650/100 = $166.5

Thus, simple interest for 1 year = $166.5

Therefore, simple interest for 9 years

= Simple interest for 1 year × 9

= $166.5 × 9 = $1498.5

Thus, Simple Interest (SI) = $1498.5

Calculation of Amount

Amount = Principal + Interest

Thus, Amount = $5550 + $1498.5

= $7048.5

Thus, Amount to be paid = $7048.5 Answer


Similar Questions

(1) Calculate the amount due after 10 years if Karen borrowed a sum of $5950 at a rate of 10% simple interest.

(2) Calculate the amount due if Karen borrowed a sum of $3950 at 4% simple interest for 4 years.

(3) What amount does David have to pay after 6 years if he takes a loan of $3400 at 4% simple interest?

(4) Andrew had to pay $5232 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.

(5) Calculate the amount due after 9 years if Thomas borrowed a sum of $5800 at a rate of 4% simple interest.

(6) Calculate the amount due after 10 years if James borrowed a sum of $5000 at a rate of 7% simple interest.

(7) Calculate the amount due if Patricia borrowed a sum of $3150 at 9% simple interest for 3 years.

(8) If Daniel paid $4592 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.

(9) William took a loan of $5000 at the rate of 8% simple interest per annum. If he paid an amount of $7400 to clear the loan, then find the time period of the loan.

(10) If Kimberly paid $5580 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.


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