Question:
Calculate the amount due if Susan borrowed a sum of $3650 at 9% simple interest for 4 years.
Correct Answer
$4964
Solution And Explanation
Solution
Given,
Principal (P) = $3650
Rate of Simple Interest (SI) = 9%
Time (t) = 4 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% × 4
= $3650 ×9/100 × 4
= 3650 × 9 × 4/100
= 32850 × 4/100
= 131400/100
= $1314
Thus, Simple Interest = $1314
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 + $1314
= $4964
Thus, Amount to be paid = $4964 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) = 4 years
Thus, Amount (A)
= $3650 + ($3650 × 9% × 4)
= $3650 + ($3650 ×9/100 × 4)
= $3650 + (3650 × 9 × 4/100)
= $3650 + (32850 × 4/100)
= $3650 + (131400/100)
= $3650 + $1314 = $4964
Thus, Amount (A) to be paid = $4964 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 4 years
= Simple interest for 1 year × 4
= $328.5 × 4 = $1314
Thus, Simple Interest (SI) = $1314
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3650 + $1314
= $4964
Thus, Amount to be paid = $4964 Answer
Similar Questions
(1) What amount does Thomas have to pay after 6 years if he takes a loan of $3800 at 8% simple interest?
(2) Calculate the amount due after 10 years if Patricia borrowed a sum of $5150 at a rate of 5% simple interest.
(3) In how much time a principal of $3200 will amount to $3328 at a simple interest of 2% per annum?
(4) Find the amount to be paid if Mary borrowed a sum of $5050 at 7% simple interest for 8 years.
(5) Calculate the amount due after 10 years if Robert borrowed a sum of $5100 at a rate of 5% simple interest.
(6) Linda took a loan of $4700 at the rate of 8% simple interest per annum. If he paid an amount of $7708 to clear the loan, then find the time period of the loan.
(7) Calculate the amount due after 10 years if Mary borrowed a sum of $5050 at a rate of 5% simple interest.
(8) Calculate the amount due after 10 years if James borrowed a sum of $5000 at a rate of 5% simple interest.
(9) Lisa took a loan of $6100 at the rate of 7% simple interest per annum. If he paid an amount of $9516 to clear the loan, then find the time period of the loan.
(10) Calculate the amount due after 10 years if Charles borrowed a sum of $5900 at a rate of 3% simple interest.