Question:
Calculate the amount due if James borrowed a sum of $3000 at 9% simple interest for 3 years.
Correct Answer
$3810
Solution And Explanation
Solution
Given,
Principal (P) = $3000
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) = $3000 × 9% × 3
= $3000 ×9/100 × 3
= 3000 × 9 × 3/100
= 27000 × 3/100
= 81000/100
= $810
Thus, Simple Interest = $810
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 = $3000 + $810
= $3810
Thus, Amount to be paid = $3810 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 = $3000
Rate of Simple Interest (SI) or (R) = 9%
And, Time (t) = 3 years
Thus, Amount (A)
= $3000 + ($3000 × 9% × 3)
= $3000 + ($3000 ×9/100 × 3)
= $3000 + (3000 × 9 × 3/100)
= $3000 + (27000 × 3/100)
= $3000 + (81000/100)
= $3000 + $810 = $3810
Thus, Amount (A) to be paid = $3810 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 $3000, the simple interest in 1 year
= 9/100 × 3000
= 9 × 3000/100
= 27000/100 = $270
Thus, simple interest for 1 year = $270
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $270 × 3 = $810
Thus, Simple Interest (SI) = $810
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3000 + $810
= $3810
Thus, Amount to be paid = $3810 Answer
Similar Questions
(1) Calculate the amount due if William borrowed a sum of $3500 at 3% simple interest for 3 years.
(2) Calculate the amount due after 10 years if Mary borrowed a sum of $5050 at a rate of 4% simple interest.
(3) David took a loan of $4800 at the rate of 7% simple interest per annum. If he paid an amount of $7824 to clear the loan, then find the time period of the loan.
(4) Calculate the amount due if John borrowed a sum of $3200 at 3% simple interest for 3 years.
(5) Calculate the amount due if James borrowed a sum of $3000 at 5% simple interest for 4 years.
(6) Jessica took a loan of $5500 at the rate of 9% simple interest per annum. If he paid an amount of $10450 to clear the loan, then find the time period of the loan.
(7) Calculate the amount due if Patricia borrowed a sum of $3150 at 10% simple interest for 4 years.
(8) Calculate the amount due after 10 years if Susan borrowed a sum of $5650 at a rate of 3% simple interest.
(9) If Donna paid $5238 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.
(10) What amount does John have to pay after 5 years if he takes a loan of $3200 at 3% simple interest?