Question:
Calculate the amount due if Joseph borrowed a sum of $3700 at 10% simple interest for 3 years.
Correct Answer
$4810
Solution And Explanation
Solution
Given,
Principal (P) = $3700
Rate of Simple Interest (SI) = 10%
Time (t) = 3 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 10% simple interest means, Rate of Simple Interest (SI) is 10% 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) = $3700 × 10% × 3
= $3700 ×10/100 × 3
= 3700 × 10 × 3/100
= 37000 × 3/100
= 111000/100
= $1110
Thus, Simple Interest = $1110
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 = $3700 + $1110
= $4810
Thus, Amount to be paid = $4810 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 = $3700
Rate of Simple Interest (SI) or (R) = 10%
And, Time (t) = 3 years
Thus, Amount (A)
= $3700 + ($3700 × 10% × 3)
= $3700 + ($3700 ×10/100 × 3)
= $3700 + (3700 × 10 × 3/100)
= $3700 + (37000 × 3/100)
= $3700 + (111000/100)
= $3700 + $1110 = $4810
Thus, Amount (A) to be paid = $4810 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 10%
This, means, $10 per $100 per year
∵ For $100, the simple interest for 1 year = $10
∴ For $1, the simple interest for 1 year = 10/100
∴ For $3700, the simple interest in 1 year
= 10/100 × 3700
= 10 × 3700/100
= 37000/100 = $370
Thus, simple interest for 1 year = $370
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $370 × 3 = $1110
Thus, Simple Interest (SI) = $1110
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3700 + $1110
= $4810
Thus, Amount to be paid = $4810 Answer
Similar Questions
(1) Calculate the amount due after 9 years if Jennifer borrowed a sum of $5250 at a rate of 10% simple interest.
(2) Calculate the amount due if James borrowed a sum of $3000 at 7% simple interest for 4 years.
(3) Calculate the amount due if Barbara borrowed a sum of $3550 at 8% simple interest for 3 years.
(4) Calculate the amount due if Sarah borrowed a sum of $3850 at 10% simple interest for 3 years.
(5) Calculate the amount due after 9 years if William borrowed a sum of $5500 at a rate of 3% simple interest.
(6) Find the amount to be paid if Mary borrowed a sum of $5050 at 3% simple interest for 7 years.
(7) Find the amount to be paid if Charles borrowed a sum of $5900 at 2% simple interest for 8 years.
(8) Christopher took a loan of $6000 at the rate of 10% simple interest per annum. If he paid an amount of $12000 to clear the loan, then find the time period of the loan.
(9) Find the amount to be paid if Jessica borrowed a sum of $5750 at 8% simple interest for 8 years.
(10) Calculate the amount due after 10 years if William borrowed a sum of $5500 at a rate of 3% simple interest.