Question:
Calculate the amount due if Sarah borrowed a sum of $3850 at 5% simple interest for 3 years.
Correct Answer
$4427.5
Solution And Explanation
Solution
Given,
Principal (P) = $3850
Rate of Simple Interest (SI) = 5%
Time (t) = 3 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 5% simple interest means, Rate of Simple Interest (SI) is 5% 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 × 5% × 3
= $3850 ×5/100 × 3
= 3850 × 5 × 3/100
= 19250 × 3/100
= 57750/100
= $577.5
Thus, Simple Interest = $577.5
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 = $3850 + $577.5
= $4427.5
Thus, Amount to be paid = $4427.5 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 = $3850
Rate of Simple Interest (SI) or (R) = 5%
And, Time (t) = 3 years
Thus, Amount (A)
= $3850 + ($3850 × 5% × 3)
= $3850 + ($3850 ×5/100 × 3)
= $3850 + (3850 × 5 × 3/100)
= $3850 + (19250 × 3/100)
= $3850 + (57750/100)
= $3850 + $577.5 = $4427.5
Thus, Amount (A) to be paid = $4427.5 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 5%
This, means, $5 per $100 per year
∵ For $100, the simple interest for 1 year = $5
∴ For $1, the simple interest for 1 year = 5/100
∴ For $3850, the simple interest in 1 year
= 5/100 × 3850
= 5 × 3850/100
= 19250/100 = $192.5
Thus, simple interest for 1 year = $192.5
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $192.5 × 3 = $577.5
Thus, Simple Interest (SI) = $577.5
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3850 + $577.5
= $4427.5
Thus, Amount to be paid = $4427.5 Answer
Similar Questions
(1) Calculate the amount due after 10 years if Richard borrowed a sum of $5600 at a rate of 5% simple interest.
(2) If Thomas borrowed $3800 from a bank at a rate of 2% simple interest per annum then find the amount to be paid after 2 years.
(3) Calculate the amount due if Jessica borrowed a sum of $3750 at 7% simple interest for 4 years.
(4) 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.
(5) Calculate the amount due if Susan borrowed a sum of $3650 at 10% simple interest for 4 years.
(6) Find the amount to be paid if Charles borrowed a sum of $5900 at 4% simple interest for 8 years.
(7) Calculate the amount due if Michael borrowed a sum of $3300 at 3% simple interest for 3 years.
(8) Barbara took a loan of $5100 at the rate of 9% simple interest per annum. If he paid an amount of $9231 to clear the loan, then find the time period of the loan.
(9) What amount does Sarah have to pay after 5 years if he takes a loan of $3850 at 9% simple interest?
(10) Find the amount to be paid if Susan borrowed a sum of $5650 at 4% simple interest for 8 years.