Question:
Calculate the amount due if Richard borrowed a sum of $3600 at 6% simple interest for 3 years.
Correct Answer
$4248
Solution And Explanation
Solution
Given,
Principal (P) = $3600
Rate of Simple Interest (SI) = 6%
Time (t) = 3 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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) = $3600 × 6% × 3
= $3600 ×6/100 × 3
= 3600 × 6 × 3/100
= 21600 × 3/100
= 64800/100
= $648
Thus, Simple Interest = $648
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 = $3600 + $648
= $4248
Thus, Amount to be paid = $4248 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 = $3600
Rate of Simple Interest (SI) or (R) = 6%
And, Time (t) = 3 years
Thus, Amount (A)
= $3600 + ($3600 × 6% × 3)
= $3600 + ($3600 ×6/100 × 3)
= $3600 + (3600 × 6 × 3/100)
= $3600 + (21600 × 3/100)
= $3600 + (64800/100)
= $3600 + $648 = $4248
Thus, Amount (A) to be paid = $4248 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 6%
This, means, $6 per $100 per year
∵ For $100, the simple interest for 1 year = $6
∴ For $1, the simple interest for 1 year = 6/100
∴ For $3600, the simple interest in 1 year
= 6/100 × 3600
= 6 × 3600/100
= 21600/100 = $216
Thus, simple interest for 1 year = $216
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $216 × 3 = $648
Thus, Simple Interest (SI) = $648
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3600 + $648
= $4248
Thus, Amount to be paid = $4248 Answer
Similar Questions
(1) Christopher took a loan of $6000 at the rate of 9% simple interest per annum. If he paid an amount of $9240 to clear the loan, then find the time period of the loan.
(2) Margaret took a loan of $6700 at the rate of 7% simple interest per annum. If he paid an amount of $9983 to clear the loan, then find the time period of the loan.
(3) If David borrowed $3400 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.
(4) Susan took a loan of $5300 at the rate of 9% simple interest per annum. If he paid an amount of $8639 to clear the loan, then find the time period of the loan.
(5) Calculate the amount due after 9 years if John borrowed a sum of $5200 at a rate of 10% simple interest.
(6) How much loan did Robert borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $5865 to clear it?
(7) If Barbara paid $3834 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.
(8) If Jennifer paid $3510 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.
(9) Karen had to pay $4305.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.
(10) Calculate the amount due after 10 years if Robert borrowed a sum of $5100 at a rate of 8% simple interest.