Question:
( 1 of 10 ) Calculate the amount due if Charles borrowed a sum of $3900 at 2% simple interest for 3 years.
(A) 59
(B) 30.5
(C) 61
(D) 60
You selected
$3900
Correct Answer
$4134
Solution And Explanation
Solution
Given,
Principal (P) = $3900
Rate of Simple Interest (SI) = 2%
Time (t) = 3 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 2% simple interest means, Rate of Simple Interest (SI) is 2% 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) = $3900 × 2% × 3
= $3900 ×2/100 × 3
= 3900 × 2 × 3/100
= 7800 × 3/100
= 23400/100
= $234
Thus, Simple Interest = $234
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 = $3900 + $234
= $4134
Thus, Amount to be paid = $4134 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 = $3900
Rate of Simple Interest (SI) or (R) = 2%
And, Time (t) = 3 years
Thus, Amount (A)
= $3900 + ($3900 × 2% × 3)
= $3900 + ($3900 ×2/100 × 3)
= $3900 + (3900 × 2 × 3/100)
= $3900 + (7800 × 3/100)
= $3900 + (23400/100)
= $3900 + $234 = $4134
Thus, Amount (A) to be paid = $4134 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 2%
This, means, $2 per $100 per year
∵ For $100, the simple interest for 1 year = $2
∴ For $1, the simple interest for 1 year = 2/100
∴ For $3900, the simple interest in 1 year
= 2/100 × 3900
= 2 × 3900/100
= 7800/100 = $78
Thus, simple interest for 1 year = $78
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $78 × 3 = $234
Thus, Simple Interest (SI) = $234
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3900 + $234
= $4134
Thus, Amount to be paid = $4134 Answer
Similar Questions
(1) Calculate the amount due after 10 years if David borrowed a sum of $5400 at a rate of 9% simple interest.
(2) In how much time a principal of $3150 will amount to $3622.5 at a simple interest of 5% per annum?
(3) Margaret took a loan of $6700 at the rate of 8% simple interest per annum. If he paid an amount of $12060 to clear the loan, then find the time period of the loan.
(4) Mary took a loan of $4100 at the rate of 7% simple interest per annum. If he paid an amount of $6396 to clear the loan, then find the time period of the loan.
(5) Linda took a loan of $4700 at the rate of 10% simple interest per annum. If he paid an amount of $7990 to clear the loan, then find the time period of the loan.
(6) Find the amount to be paid if David borrowed a sum of $5400 at 4% simple interest for 8 years.
(7) Calculate the amount due if Christopher borrowed a sum of $4000 at 4% simple interest for 3 years.
(8) If Andrew paid $5760 to settle his loan which he had taken 4 years before at a simple interest of 5%, then find the loan taken.
(9) Richard had to pay $3924 in order to furnish the loan taken 3 years before. If the rate of simple interest was 3% then find the sum borrowed.
(10) Calculate the amount due after 9 years if Susan borrowed a sum of $5650 at a rate of 5% simple interest.