Question:
What amount will be due after 2 years if Kenneth borrowed a sum of $4000 at a 8% simple interest?
Correct Answer
$4640
Solution And Explanation
Solution
Given,
Principal (P) = $4000
Rate of Simple Interest (SI) = 8%
Time (t) = 2 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 8% simple interest means, Rate of Simple Interest (SI) is 8% 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) = $4000 × 8% × 2
= $4000 ×8/100 × 2
= 4000 × 8 × 2/100
= 32000 × 2/100
= 64000/100
= $640
Thus, Simple Interest = $640
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 = $4000 + $640
= $4640
Thus, Amount to be paid = $4640 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 = $4000
Rate of Simple Interest (SI) or (R) = 8%
And, Time (t) = 2 years
Thus, Amount (A)
= $4000 + ($4000 × 8% × 2)
= $4000 + ($4000 ×8/100 × 2)
= $4000 + (4000 × 8 × 2/100)
= $4000 + (32000 × 2/100)
= $4000 + (64000/100)
= $4000 + $640 = $4640
Thus, Amount (A) to be paid = $4640 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 8%
This, means, $8 per $100 per year
∵ For $100, the simple interest for 1 year = $8
∴ For $1, the simple interest for 1 year = 8/100
∴ For $4000, the simple interest in 1 year
= 8/100 × 4000
= 8 × 4000/100
= 32000/100 = $320
Thus, simple interest for 1 year = $320
Therefore, simple interest for 2 years
= Simple interest for 1 year × 2
= $320 × 2 = $640
Thus, Simple Interest (SI) = $640
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $4000 + $640
= $4640
Thus, Amount to be paid = $4640 Answer
Similar Questions
(1) Calculate the amount due after 9 years if David borrowed a sum of $5400 at a rate of 5% simple interest.
(2) William took a loan of $5000 at the rate of 8% simple interest per annum. If he paid an amount of $7800 to clear the loan, then find the time period of the loan.
(3) What amount does Karen have to pay after 5 years if he takes a loan of $3950 at 2% simple interest?
(4) Sandra took a loan of $6900 at the rate of 6% simple interest per annum. If he paid an amount of $9798 to clear the loan, then find the time period of the loan.
(5) Calculate the amount due after 9 years if Jessica borrowed a sum of $5750 at a rate of 5% simple interest.
(6) Find the amount to be paid if Sarah borrowed a sum of $5850 at 9% simple interest for 7 years.
(7) Calculate the amount due after 9 years if Karen borrowed a sum of $5950 at a rate of 9% simple interest.
(8) What amount does Joseph have to pay after 5 years if he takes a loan of $3700 at 8% simple interest?
(9) How much loan did Paul borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $7705 to clear it?
(10) Calculate the amount due after 10 years if Patricia borrowed a sum of $5150 at a rate of 2% simple interest.