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) Calculate the amount due after 10 years if Charles borrowed a sum of $5900 at a rate of 4% simple interest.
(2) What amount does Thomas have to pay after 5 years if he takes a loan of $3800 at 5% simple interest?
(3) Linda took a loan of $4700 at the rate of 10% simple interest per annum. If he paid an amount of $8460 to clear the loan, then find the time period of the loan.
(4) What amount does Barbara have to pay after 6 years if he takes a loan of $3550 at 4% simple interest?
(5) Mary took a loan of $4100 at the rate of 7% simple interest per annum. If he paid an amount of $6683 to clear the loan, then find the time period of the loan.
(6) How much loan did Linda borrow 5 years ago at a rate of simple interest 2% per annum, if he paid $5885 to clear it?
(7) How much loan did Sarah borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $7020 to clear it?
(8) Calculate the amount due after 9 years if Sarah borrowed a sum of $5850 at a rate of 2% simple interest.
(9) Calculate the amount due after 9 years if Charles borrowed a sum of $5900 at a rate of 4% simple interest.
(10) What amount does Michael have to pay after 5 years if he takes a loan of $3300 at 10% simple interest?