Question:
What amount does William have to pay after 6 years if he takes a loan of $3500 at 9% simple interest?
Correct Answer
$5390
Solution And Explanation
Solution
Given,
Principal (P) = $3500
Rate of Simple Interest (SI) = 9%
Time (t) = 6 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) = $3500 × 9% × 6
= $3500 ×9/100 × 6
= 3500 × 9 × 6/100
= 31500 × 6/100
= 189000/100
= $1890
Thus, Simple Interest = $1890
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 = $3500 + $1890
= $5390
Thus, Amount to be paid = $5390 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 = $3500
Rate of Simple Interest (SI) or (R) = 9%
And, Time (t) = 6 years
Thus, Amount (A)
= $3500 + ($3500 × 9% × 6)
= $3500 + ($3500 ×9/100 × 6)
= $3500 + (3500 × 9 × 6/100)
= $3500 + (31500 × 6/100)
= $3500 + (189000/100)
= $3500 + $1890 = $5390
Thus, Amount (A) to be paid = $5390 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 $3500, the simple interest in 1 year
= 9/100 × 3500
= 9 × 3500/100
= 31500/100 = $315
Thus, simple interest for 1 year = $315
Therefore, simple interest for 6 years
= Simple interest for 1 year × 6
= $315 × 6 = $1890
Thus, Simple Interest (SI) = $1890
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3500 + $1890
= $5390
Thus, Amount to be paid = $5390 Answer
Similar Questions
(1) What amount does Karen have to pay after 5 years if he takes a loan of $3950 at 8% simple interest?
(2) How much loan did Joseph borrow 5 years ago at a rate of simple interest 4% per annum, if he paid $6840 to clear it?
(3) Donald took a loan of $7000 at the rate of 7% simple interest per annum. If he paid an amount of $10430 to clear the loan, then find the time period of the loan.
(4) Donald took a loan of $7000 at the rate of 7% simple interest per annum. If he paid an amount of $9940 to clear the loan, then find the time period of the loan.
(5) Donald took a loan of $7000 at the rate of 9% simple interest per annum. If he paid an amount of $10780 to clear the loan, then find the time period of the loan.
(6) What amount will be due after 2 years if Michael borrowed a sum of $3150 at a 4% simple interest?
(7) Find the amount to be paid if Jessica borrowed a sum of $5750 at 7% simple interest for 7 years.
(8) Find the amount to be paid if Charles borrowed a sum of $5900 at 3% simple interest for 7 years.
(9) Mary took a loan of $4100 at the rate of 6% simple interest per annum. If he paid an amount of $5822 to clear the loan, then find the time period of the loan.
(10) What amount will be due after 2 years if Richard borrowed a sum of $3300 at a 9% simple interest?