Question:
Calculate the amount due if Richard borrowed a sum of $3600 at 6% simple interest for 4 years.
Correct Answer
$4464
Solution And Explanation
Solution
Given,
Principal (P) = $3600
Rate of Simple Interest (SI) = 6%
Time (t) = 4 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% × 4
= $3600 ×6/100 × 4
= 3600 × 6 × 4/100
= 21600 × 4/100
= 86400/100
= $864
Thus, Simple Interest = $864
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 + $864
= $4464
Thus, Amount to be paid = $4464 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) = 4 years
Thus, Amount (A)
= $3600 + ($3600 × 6% × 4)
= $3600 + ($3600 ×6/100 × 4)
= $3600 + (3600 × 6 × 4/100)
= $3600 + (21600 × 4/100)
= $3600 + (86400/100)
= $3600 + $864 = $4464
Thus, Amount (A) to be paid = $4464 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 4 years
= Simple interest for 1 year × 4
= $216 × 4 = $864
Thus, Simple Interest (SI) = $864
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3600 + $864
= $4464
Thus, Amount to be paid = $4464 Answer
Similar Questions
(1) Robert took a loan of $4200 at the rate of 10% simple interest per annum. If he paid an amount of $7140 to clear the loan, then find the time period of the loan.
(2) Thomas took a loan of $5600 at the rate of 7% simple interest per annum. If he paid an amount of $9128 to clear the loan, then find the time period of the loan.
(3) Mark took a loan of $6800 at the rate of 9% simple interest per annum. If he paid an amount of $12308 to clear the loan, then find the time period of the loan.
(4) What amount does Robert have to pay after 6 years if he takes a loan of $3100 at 2% simple interest?
(5) Sarah took a loan of $5700 at the rate of 10% simple interest per annum. If he paid an amount of $9690 to clear the loan, then find the time period of the loan.
(6) Jessica took a loan of $5500 at the rate of 10% simple interest per annum. If he paid an amount of $8800 to clear the loan, then find the time period of the loan.
(7) Mary took a loan of $4100 at the rate of 6% simple interest per annum. If he paid an amount of $6314 to clear the loan, then find the time period of the loan.
(8) What amount does Karen have to pay after 6 years if he takes a loan of $3950 at 2% simple interest?
(9) What amount does Joseph have to pay after 6 years if he takes a loan of $3700 at 7% simple interest?
(10) Calculate the amount due if Thomas borrowed a sum of $3800 at 8% simple interest for 4 years.