Question:
What amount will be due after 2 years if Kenneth borrowed a sum of $4000 at a 10% simple interest?
Correct Answer
$4800
Solution And Explanation
Solution
Given,
Principal (P) = $4000
Rate of Simple Interest (SI) = 10%
Time (t) = 2 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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 × 10% × 2
= $4000 ×10/100 × 2
= 4000 × 10 × 2/100
= 40000 × 2/100
= 80000/100
= $800
Thus, Simple Interest = $800
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 + $800
= $4800
Thus, Amount to be paid = $4800 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) = 10%
And, Time (t) = 2 years
Thus, Amount (A)
= $4000 + ($4000 × 10% × 2)
= $4000 + ($4000 ×10/100 × 2)
= $4000 + (4000 × 10 × 2/100)
= $4000 + (40000 × 2/100)
= $4000 + (80000/100)
= $4000 + $800 = $4800
Thus, Amount (A) to be paid = $4800 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 10%
This, means, $10 per $100 per year
∵ For $100, the simple interest for 1 year = $10
∴ For $1, the simple interest for 1 year = 10/100
∴ For $4000, the simple interest in 1 year
= 10/100 × 4000
= 10 × 4000/100
= 40000/100 = $400
Thus, simple interest for 1 year = $400
Therefore, simple interest for 2 years
= Simple interest for 1 year × 2
= $400 × 2 = $800
Thus, Simple Interest (SI) = $800
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $4000 + $800
= $4800
Thus, Amount to be paid = $4800 Answer
Similar Questions
(1) Find the amount to be paid if Thomas borrowed a sum of $5800 at 6% simple interest for 8 years.
(2) What amount does Sarah have to pay after 5 years if he takes a loan of $3850 at 5% simple interest?
(3) Calculate the amount due after 10 years if Linda borrowed a sum of $5350 at a rate of 6% simple interest.
(4) Calculate the amount due if Jennifer borrowed a sum of $3250 at 7% simple interest for 3 years.
(5) Calculate the amount due if Michael borrowed a sum of $3300 at 5% simple interest for 4 years.
(6) What amount will be due after 2 years if Michael borrowed a sum of $3150 at a 7% simple interest?
(7) Find the amount to be paid if Christopher borrowed a sum of $6000 at 7% simple interest for 8 years.
(8) In how much time a principal of $3050 will amount to $3324.5 at a simple interest of 3% per annum?
(9) Barbara had to pay $3976 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.
(10) Calculate the amount due if William borrowed a sum of $3500 at 9% simple interest for 3 years.