Question:
Calculate the amount due after 9 years if Thomas borrowed a sum of $5800 at a rate of 8% simple interest.
Correct Answer
$9976
Solution And Explanation
Solution
Given,
Principal (P) = $5800
Rate of Simple Interest (SI) = 8%
Time (t) = 9 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) = $5800 × 8% × 9
= $5800 ×8/100 × 9
= 5800 × 8 × 9/100
= 46400 × 9/100
= 417600/100
= $4176
Thus, Simple Interest = $4176
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 + $4176
= $9976
Thus, Amount to be paid = $9976 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) = 8%
And, Time (t) = 9 years
Thus, Amount (A)
= $5800 + ($5800 × 8% × 9)
= $5800 + ($5800 ×8/100 × 9)
= $5800 + (5800 × 8 × 9/100)
= $5800 + (46400 × 9/100)
= $5800 + (417600/100)
= $5800 + $4176 = $9976
Thus, Amount (A) to be paid = $9976 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 $5800, the simple interest in 1 year
= 8/100 × 5800
= 8 × 5800/100
= 46400/100 = $464
Thus, simple interest for 1 year = $464
Therefore, simple interest for 9 years
= Simple interest for 1 year × 9
= $464 × 9 = $4176
Thus, Simple Interest (SI) = $4176
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $5800 + $4176
= $9976
Thus, Amount to be paid = $9976 Answer
Similar Questions
(1) Calculate the amount due if Robert borrowed a sum of $3100 at 10% simple interest for 4 years.
(2) How much loan did Joshua borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $8625 to clear it?
(3) Find the amount to be paid if Christopher borrowed a sum of $6000 at 5% simple interest for 7 years.
(4) Joseph took a loan of $5400 at the rate of 8% simple interest per annum. If he paid an amount of $8424 to clear the loan, then find the time period of the loan.
(5) Calculate the amount due if Robert borrowed a sum of $3100 at 5% simple interest for 3 years.
(6) How much loan did Barbara borrow 5 years ago at a rate of simple interest 3% per annum, if he paid $6382.5 to clear it?
(7) Calculate the amount due after 10 years if Richard borrowed a sum of $5600 at a rate of 7% simple interest.
(8) Calculate the amount due if Charles borrowed a sum of $3900 at 4% simple interest for 3 years.
(9) In how much time a principal of $3100 will amount to $3565 at a simple interest of 5% per annum?
(10) Calculate the amount due after 9 years if John borrowed a sum of $5200 at a rate of 5% simple interest.