Question:
Calculate the amount due if John borrowed a sum of $3200 at 6% simple interest for 3 years.
Correct Answer
$3776
Solution And Explanation
Solution
Given,
Principal (P) = $3200
Rate of Simple Interest (SI) = 6%
Time (t) = 3 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 6% simple interest means, Rate of Simple Interest (SI) is 6% 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) = $3200 × 6% × 3
= $3200 ×6/100 × 3
= 3200 × 6 × 3/100
= 19200 × 3/100
= 57600/100
= $576
Thus, Simple Interest = $576
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 = $3200 + $576
= $3776
Thus, Amount to be paid = $3776 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 = $3200
Rate of Simple Interest (SI) or (R) = 6%
And, Time (t) = 3 years
Thus, Amount (A)
= $3200 + ($3200 × 6% × 3)
= $3200 + ($3200 ×6/100 × 3)
= $3200 + (3200 × 6 × 3/100)
= $3200 + (19200 × 3/100)
= $3200 + (57600/100)
= $3200 + $576 = $3776
Thus, Amount (A) to be paid = $3776 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 6%
This, means, $6 per $100 per year
∵ For $100, the simple interest for 1 year = $6
∴ For $1, the simple interest for 1 year = 6/100
∴ For $3200, the simple interest in 1 year
= 6/100 × 3200
= 6 × 3200/100
= 19200/100 = $192
Thus, simple interest for 1 year = $192
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $192 × 3 = $576
Thus, Simple Interest (SI) = $576
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3200 + $576
= $3776
Thus, Amount to be paid = $3776 Answer
Similar Questions
(1) Calculate the amount due if Robert borrowed a sum of $3100 at 9% simple interest for 3 years.
(2) Calculate the amount due if James borrowed a sum of $3000 at 6% simple interest for 3 years.
(3) Linda took a loan of $4700 at the rate of 8% simple interest per annum. If he paid an amount of $8084 to clear the loan, then find the time period of the loan.
(4) Barbara took a loan of $5100 at the rate of 8% simple interest per annum. If he paid an amount of $9180 to clear the loan, then find the time period of the loan.
(5) What amount will be due after 2 years if Charles borrowed a sum of $3450 at a 8% simple interest?
(6) Lisa took a loan of $6100 at the rate of 10% simple interest per annum. If he paid an amount of $11590 to clear the loan, then find the time period of the loan.
(7) Calculate the amount due after 10 years if Robert borrowed a sum of $5100 at a rate of 8% simple interest.
(8) Charles took a loan of $5800 at the rate of 7% simple interest per annum. If he paid an amount of $8642 to clear the loan, then find the time period of the loan.
(9) Find the amount to be paid if Elizabeth borrowed a sum of $5450 at 9% simple interest for 7 years.
(10) What amount will be due after 2 years if Andrew borrowed a sum of $3900 at a 7% simple interest?