Question:
Calculate the amount due after 9 years if Christopher borrowed a sum of $6000 at a rate of 2% simple interest.
Correct Answer
$7080
Solution And Explanation
Solution
Given,
Principal (P) = $6000
Rate of Simple Interest (SI) = 2%
Time (t) = 9 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 2% simple interest means, Rate of Simple Interest (SI) is 2% 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) = $6000 × 2% × 9
= $6000 ×2/100 × 9
= 6000 × 2 × 9/100
= 12000 × 9/100
= 108000/100
= $1080
Thus, Simple Interest = $1080
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 = $6000 + $1080
= $7080
Thus, Amount to be paid = $7080 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 = $6000
Rate of Simple Interest (SI) or (R) = 2%
And, Time (t) = 9 years
Thus, Amount (A)
= $6000 + ($6000 × 2% × 9)
= $6000 + ($6000 ×2/100 × 9)
= $6000 + (6000 × 2 × 9/100)
= $6000 + (12000 × 9/100)
= $6000 + (108000/100)
= $6000 + $1080 = $7080
Thus, Amount (A) to be paid = $7080 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 2%
This, means, $2 per $100 per year
∵ For $100, the simple interest for 1 year = $2
∴ For $1, the simple interest for 1 year = 2/100
∴ For $6000, the simple interest in 1 year
= 2/100 × 6000
= 2 × 6000/100
= 12000/100 = $120
Thus, simple interest for 1 year = $120
Therefore, simple interest for 9 years
= Simple interest for 1 year × 9
= $120 × 9 = $1080
Thus, Simple Interest (SI) = $1080
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $6000 + $1080
= $7080
Thus, Amount to be paid = $7080 Answer
Similar Questions
(1) Calculate the amount due if Christopher borrowed a sum of $4000 at 2% simple interest for 3 years.
(2) Calculate the amount due after 9 years if James borrowed a sum of $5000 at a rate of 6% simple interest.
(3) Mary had to pay $3507.5 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.
(4) Find the amount to be paid if Richard borrowed a sum of $5600 at 9% simple interest for 7 years.
(5) Calculate the amount due if Thomas borrowed a sum of $3800 at 8% simple interest for 3 years.
(6) What amount will be due after 2 years if Daniel borrowed a sum of $3550 at a 5% simple interest?
(7) Calculate the amount due if Christopher borrowed a sum of $4000 at 3% simple interest for 3 years.
(8) Calculate the amount due if Thomas borrowed a sum of $3800 at 6% simple interest for 3 years.
(9) Anthony had to pay $4558 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.
(10) In how much time a principal of $3200 will amount to $3680 at a simple interest of 3% per annum?