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) In how much time a principal of $3200 will amount to $4000 at a simple interest of 5% per annum?
(2) If Christopher paid $4640 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.
(3) Calculate the amount due if Charles borrowed a sum of $3900 at 6% simple interest for 3 years.
(4) Anthony took a loan of $6600 at the rate of 9% simple interest per annum. If he paid an amount of $10758 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 $11410 to clear the loan, then find the time period of the loan.
(6) Calculate the amount due if Linda borrowed a sum of $3350 at 8% simple interest for 3 years.
(7) Ashley had to pay $5096 in order to furnish the loan taken 3 years before. If the rate of simple interest was 4% then find the sum borrowed.
(8) Find the amount to be paid if David borrowed a sum of $5400 at 2% simple interest for 8 years.
(9) What amount does Patricia have to pay after 6 years if he takes a loan of $3150 at 8% simple interest?
(10) Susan took a loan of $5300 at the rate of 7% simple interest per annum. If he paid an amount of $8268 to clear the loan, then find the time period of the loan.