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) What amount does Robert have to pay after 5 years if he takes a loan of $3100 at 9% simple interest?
(2) What amount does John have to pay after 6 years if he takes a loan of $3200 at 7% simple interest?
(3) Charles took a loan of $5800 at the rate of 8% simple interest per annum. If he paid an amount of $8584 to clear the loan, then find the time period of the loan.
(4) What amount does Mary have to pay after 6 years if he takes a loan of $3050 at 5% simple interest?
(5) Calculate the amount due after 9 years if Susan borrowed a sum of $5650 at a rate of 3% simple interest.
(6) Mary took a loan of $4100 at the rate of 6% simple interest per annum. If he paid an amount of $5822 to clear the loan, then find the time period of the loan.
(7) Matthew had to pay $4578 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.
(8) Jennifer took a loan of $4500 at the rate of 8% simple interest per annum. If he paid an amount of $7380 to clear the loan, then find the time period of the loan.
(9) Find the amount to be paid if James borrowed a sum of $5000 at 9% simple interest for 7 years.
(10) Elizabeth took a loan of $4900 at the rate of 9% simple interest per annum. If he paid an amount of $8869 to clear the loan, then find the time period of the loan.