Question:
Calculate the amount due if Thomas borrowed a sum of $3800 at 9% simple interest for 3 years.
Correct Answer
$4826
Solution And Explanation
Solution
Given,
Principal (P) = $3800
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) = $3800 × 9% × 3
= $3800 ×9/100 × 3
= 3800 × 9 × 3/100
= 34200 × 3/100
= 102600/100
= $1026
Thus, Simple Interest = $1026
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 = $3800 + $1026
= $4826
Thus, Amount to be paid = $4826 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 = $3800
Rate of Simple Interest (SI) or (R) = 9%
And, Time (t) = 3 years
Thus, Amount (A)
= $3800 + ($3800 × 9% × 3)
= $3800 + ($3800 ×9/100 × 3)
= $3800 + (3800 × 9 × 3/100)
= $3800 + (34200 × 3/100)
= $3800 + (102600/100)
= $3800 + $1026 = $4826
Thus, Amount (A) to be paid = $4826 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 $3800, the simple interest in 1 year
= 9/100 × 3800
= 9 × 3800/100
= 34200/100 = $342
Thus, simple interest for 1 year = $342
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $342 × 3 = $1026
Thus, Simple Interest (SI) = $1026
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3800 + $1026
= $4826
Thus, Amount to be paid = $4826 Answer
Similar Questions
(1) Calculate the amount due if Elizabeth borrowed a sum of $3450 at 4% simple interest for 3 years.
(2) Find the amount to be paid if Jessica borrowed a sum of $5750 at 2% simple interest for 7 years.
(3) If Christopher paid $4800 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.
(4) Calculate the amount due if Michael borrowed a sum of $3300 at 10% simple interest for 4 years.
(5) How much loan did Jennifer borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $5775 to clear it?
(6) Calculate the amount due if Karen borrowed a sum of $3950 at 5% simple interest for 4 years.
(7) How much loan did Donna borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7877.5 to clear it?
(8) Michael took a loan of $4600 at the rate of 9% simple interest per annum. If he paid an amount of $8740 to clear the loan, then find the time period of the loan.
(9) Calculate the amount due after 10 years if Sarah borrowed a sum of $5850 at a rate of 7% simple interest.
(10) What amount does Charles have to pay after 5 years if he takes a loan of $3900 at 2% simple interest?