Question:
Calculate the amount due if Richard borrowed a sum of $3600 at 3% simple interest for 4 years.
Correct Answer
$4032
Solution And Explanation
Solution
Given,
Principal (P) = $3600
Rate of Simple Interest (SI) = 3%
Time (t) = 4 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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 × 3% × 4
= $3600 ×3/100 × 4
= 3600 × 3 × 4/100
= 10800 × 4/100
= 43200/100
= $432
Thus, Simple Interest = $432
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 + $432
= $4032
Thus, Amount to be paid = $4032 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) = 3%
And, Time (t) = 4 years
Thus, Amount (A)
= $3600 + ($3600 × 3% × 4)
= $3600 + ($3600 ×3/100 × 4)
= $3600 + (3600 × 3 × 4/100)
= $3600 + (10800 × 4/100)
= $3600 + (43200/100)
= $3600 + $432 = $4032
Thus, Amount (A) to be paid = $4032 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 3%
This, means, $3 per $100 per year
∵ For $100, the simple interest for 1 year = $3
∴ For $1, the simple interest for 1 year = 3/100
∴ For $3600, the simple interest in 1 year
= 3/100 × 3600
= 3 × 3600/100
= 10800/100 = $108
Thus, simple interest for 1 year = $108
Therefore, simple interest for 4 years
= Simple interest for 1 year × 4
= $108 × 4 = $432
Thus, Simple Interest (SI) = $432
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3600 + $432
= $4032
Thus, Amount to be paid = $4032 Answer
Similar Questions
(1) Find the amount to be paid if John borrowed a sum of $5200 at 3% simple interest for 8 years.
(2) Calculate the amount due after 10 years if Elizabeth borrowed a sum of $5450 at a rate of 8% simple interest.
(3) What amount does Robert have to pay after 6 years if he takes a loan of $3100 at 2% simple interest?
(4) Patricia took a loan of $4300 at the rate of 6% simple interest per annum. If he paid an amount of $6106 to clear the loan, then find the time period of the loan.
(5) What amount does William have to pay after 6 years if he takes a loan of $3500 at 4% simple interest?
(6) How much loan did Jessica borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6900 to clear it?
(7) Christopher had to pay $4600 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.
(8) Calculate the amount due if Thomas borrowed a sum of $3800 at 10% simple interest for 4 years.
(9) Richard took a loan of $5200 at the rate of 10% simple interest per annum. If he paid an amount of $9360 to clear the loan, then find the time period of the loan.
(10) Anthony took a loan of $6600 at the rate of 10% simple interest per annum. If he paid an amount of $12540 to clear the loan, then find the time period of the loan.