Question:
What amount does Susan have to pay after 6 years if he takes a loan of $3650 at 9% simple interest?
Correct Answer
$5621
Solution And Explanation
Solution
Given,
Principal (P) = $3650
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) = $3650 × 9% × 6
= $3650 ×9/100 × 6
= 3650 × 9 × 6/100
= 32850 × 6/100
= 197100/100
= $1971
Thus, Simple Interest = $1971
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 = $3650 + $1971
= $5621
Thus, Amount to be paid = $5621 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 = $3650
Rate of Simple Interest (SI) or (R) = 9%
And, Time (t) = 6 years
Thus, Amount (A)
= $3650 + ($3650 × 9% × 6)
= $3650 + ($3650 ×9/100 × 6)
= $3650 + (3650 × 9 × 6/100)
= $3650 + (32850 × 6/100)
= $3650 + (197100/100)
= $3650 + $1971 = $5621
Thus, Amount (A) to be paid = $5621 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 $3650, the simple interest in 1 year
= 9/100 × 3650
= 9 × 3650/100
= 32850/100 = $328.5
Thus, simple interest for 1 year = $328.5
Therefore, simple interest for 6 years
= Simple interest for 1 year × 6
= $328.5 × 6 = $1971
Thus, Simple Interest (SI) = $1971
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3650 + $1971
= $5621
Thus, Amount to be paid = $5621 Answer
Similar Questions
(1) Find the amount to be paid if Patricia borrowed a sum of $5150 at 6% simple interest for 7 years.
(2) Calculate the amount due if Jennifer borrowed a sum of $3250 at 10% simple interest for 3 years.
(3) Find the amount to be paid if Joseph borrowed a sum of $5700 at 9% simple interest for 8 years.
(4) Calculate the amount due if David borrowed a sum of $3400 at 5% simple interest for 4 years.
(5) Find the amount to be paid if David borrowed a sum of $5400 at 6% simple interest for 8 years.
(6) Elizabeth had to pay $3864 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.
(7) Sandra took a loan of $6900 at the rate of 7% simple interest per annum. If he paid an amount of $9798 to clear the loan, then find the time period of the loan.
(8) David had to pay $3910 in order to furnish the loan taken 3 years before. If the rate of simple interest was 5% then find the sum borrowed.
(9) Barbara had to pay $3763 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 $3150 will amount to $3780 at a simple interest of 5% per annum?