Question:
Calculate the amount due after 9 years if Thomas borrowed a sum of $5800 at a rate of 3% simple interest.
Correct Answer
$7366
Solution And Explanation
Solution
Given,
Principal (P) = $5800
Rate of Simple Interest (SI) = 3%
Time (t) = 9 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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 × 3% × 9
= $5800 ×3/100 × 9
= 5800 × 3 × 9/100
= 17400 × 9/100
= 156600/100
= $1566
Thus, Simple Interest = $1566
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 + $1566
= $7366
Thus, Amount to be paid = $7366 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) = 3%
And, Time (t) = 9 years
Thus, Amount (A)
= $5800 + ($5800 × 3% × 9)
= $5800 + ($5800 ×3/100 × 9)
= $5800 + (5800 × 3 × 9/100)
= $5800 + (17400 × 9/100)
= $5800 + (156600/100)
= $5800 + $1566 = $7366
Thus, Amount (A) to be paid = $7366 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 3%
This, means, $3 per $100 per year
∵ For $100, the simple interest for 1 year = $3
∴ For $1, the simple interest for 1 year = 3/100
∴ For $5800, the simple interest in 1 year
= 3/100 × 5800
= 3 × 5800/100
= 17400/100 = $174
Thus, simple interest for 1 year = $174
Therefore, simple interest for 9 years
= Simple interest for 1 year × 9
= $174 × 9 = $1566
Thus, Simple Interest (SI) = $1566
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $5800 + $1566
= $7366
Thus, Amount to be paid = $7366 Answer
Similar Questions
(1) Calculate the amount due if Robert borrowed a sum of $3100 at 5% simple interest for 3 years.
(2) What amount will be due after 2 years if Kenneth borrowed a sum of $4000 at a 9% simple interest?
(3) James took a loan of $4000 at the rate of 8% simple interest per annum. If he paid an amount of $6880 to clear the loan, then find the time period of the loan.
(4) If William paid $3920 to settle his loan which he had taken 4 years before at a simple interest of 3%, then find the loan taken.
(5) Find the amount to be paid if John borrowed a sum of $5200 at 5% simple interest for 7 years.
(6) Calculate the amount due after 9 years if Barbara borrowed a sum of $5550 at a rate of 5% simple interest.
(7) If David paid $3672 to settle his loan which he had taken 4 years before at a simple interest of 2%, then find the loan taken.
(8) Thomas took a loan of $5600 at the rate of 10% simple interest per annum. If he paid an amount of $10080 to clear the loan, then find the time period of the loan.
(9) Find the amount to be paid if John borrowed a sum of $5200 at 8% simple interest for 8 years.
(10) How much loan did Mary borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6060 to clear it?