Question:
Calculate the amount due if Jessica borrowed a sum of $3750 at 9% simple interest for 4 years.
Correct Answer
$5100
Solution And Explanation
Solution
Given,
Principal (P) = $3750
Rate of Simple Interest (SI) = 9%
Time (t) = 4 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) = $3750 × 9% × 4
= $3750 ×9/100 × 4
= 3750 × 9 × 4/100
= 33750 × 4/100
= 135000/100
= $1350
Thus, Simple Interest = $1350
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 = $3750 + $1350
= $5100
Thus, Amount to be paid = $5100 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 = $3750
Rate of Simple Interest (SI) or (R) = 9%
And, Time (t) = 4 years
Thus, Amount (A)
= $3750 + ($3750 × 9% × 4)
= $3750 + ($3750 ×9/100 × 4)
= $3750 + (3750 × 9 × 4/100)
= $3750 + (33750 × 4/100)
= $3750 + (135000/100)
= $3750 + $1350 = $5100
Thus, Amount (A) to be paid = $5100 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 $3750, the simple interest in 1 year
= 9/100 × 3750
= 9 × 3750/100
= 33750/100 = $337.5
Thus, simple interest for 1 year = $337.5
Therefore, simple interest for 4 years
= Simple interest for 1 year × 4
= $337.5 × 4 = $1350
Thus, Simple Interest (SI) = $1350
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3750 + $1350
= $5100
Thus, Amount to be paid = $5100 Answer
Similar Questions
(1) Sandra took a loan of $6900 at the rate of 7% simple interest per annum. If he paid an amount of $11247 to clear the loan, then find the time period of the loan.
(2) What amount will be due after 2 years if Michael borrowed a sum of $3150 at a 8% simple interest?
(3) If Linda paid $3618 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.
(4) Thomas took a loan of $5600 at the rate of 9% simple interest per annum. If he paid an amount of $10136 to clear the loan, then find the time period of the loan.
(5) 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.
(6) What amount does Charles have to pay after 6 years if he takes a loan of $3900 at 9% simple interest?
(7) William had to pay $3815 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.
(8) If John paid $3456 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.
(9) Charles took a loan of $5800 at the rate of 8% simple interest per annum. If he paid an amount of $8584 to clear the loan, then find the time period of the loan.
(10) How much loan did Christopher borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $7500 to clear it?