Question:
Calculate the amount due after 9 years if Thomas borrowed a sum of $5800 at a rate of 9% simple interest.
Correct Answer
$10498
Solution And Explanation
Solution
Given,
Principal (P) = $5800
Rate of Simple Interest (SI) = 9%
Time (t) = 9 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% 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) = $5800 × 9% × 9
= $5800 ×9/100 × 9
= 5800 × 9 × 9/100
= 52200 × 9/100
= 469800/100
= $4698
Thus, Simple Interest = $4698
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 = $5800 + $4698
= $10498
Thus, Amount to be paid = $10498 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 = $5800
Rate of Simple Interest (SI) or (R) = 9%
And, Time (t) = 9 years
Thus, Amount (A)
= $5800 + ($5800 × 9% × 9)
= $5800 + ($5800 ×9/100 × 9)
= $5800 + (5800 × 9 × 9/100)
= $5800 + (52200 × 9/100)
= $5800 + (469800/100)
= $5800 + $4698 = $10498
Thus, Amount (A) to be paid = $10498 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 9%
This, means, $9 per $100 per year
∵ For $100, the simple interest for 1 year = $9
∴ For $1, the simple interest for 1 year = 9/100
∴ For $5800, the simple interest in 1 year
= 9/100 × 5800
= 9 × 5800/100
= 52200/100 = $522
Thus, simple interest for 1 year = $522
Therefore, simple interest for 9 years
= Simple interest for 1 year × 9
= $522 × 9 = $4698
Thus, Simple Interest (SI) = $4698
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $5800 + $4698
= $10498
Thus, Amount to be paid = $10498 Answer
Similar Questions
(1) Donald had to pay $4770 in order to furnish the loan taken 3 years before. If the rate of simple interest was 2% then find the sum borrowed.
(2) In how much time a principal of $3200 will amount to $3584 at a simple interest of 4% per annum?
(3) If Charles borrowed $3900 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.
(4) Calculate the amount due after 9 years if Michael borrowed a sum of $5300 at a rate of 8% simple interest.
(5) Calculate the amount due if John borrowed a sum of $3200 at 2% simple interest for 4 years.
(6) Calculate the amount due after 10 years if Richard borrowed a sum of $5600 at a rate of 5% simple interest.
(7) Calculate the amount due if Charles borrowed a sum of $3900 at 3% simple interest for 3 years.
(8) How much loan did George borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $8395 to clear it?
(9) Calculate the amount due if Richard borrowed a sum of $3600 at 7% simple interest for 3 years.
(10) Calculate the amount due if Karen borrowed a sum of $3950 at 7% simple interest for 3 years.