Question:
Calculate the amount due after 9 years if Christopher borrowed a sum of $6000 at a rate of 3% simple interest.
Correct Answer
$7620
Solution And Explanation
Solution
Given,
Principal (P) = $6000
Rate of Simple Interest (SI) = 3%
Time (t) = 9 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 3% simple interest means, Rate of Simple Interest (SI) is 3% 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) = $6000 × 3% × 9
= $6000 ×3/100 × 9
= 6000 × 3 × 9/100
= 18000 × 9/100
= 162000/100
= $1620
Thus, Simple Interest = $1620
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 = $6000 + $1620
= $7620
Thus, Amount to be paid = $7620 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 = $6000
Rate of Simple Interest (SI) or (R) = 3%
And, Time (t) = 9 years
Thus, Amount (A)
= $6000 + ($6000 × 3% × 9)
= $6000 + ($6000 ×3/100 × 9)
= $6000 + (6000 × 3 × 9/100)
= $6000 + (18000 × 9/100)
= $6000 + (162000/100)
= $6000 + $1620 = $7620
Thus, Amount (A) to be paid = $7620 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 3%
This, means, $3 per $100 per year
∵ For $100, the simple interest for 1 year = $3
∴ For $1, the simple interest for 1 year = 3/100
∴ For $6000, the simple interest in 1 year
= 3/100 × 6000
= 3 × 6000/100
= 18000/100 = $180
Thus, simple interest for 1 year = $180
Therefore, simple interest for 9 years
= Simple interest for 1 year × 9
= $180 × 9 = $1620
Thus, Simple Interest (SI) = $1620
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $6000 + $1620
= $7620
Thus, Amount to be paid = $7620 Answer
Similar Questions
(1) Charles took a loan of $5800 at the rate of 8% simple interest per annum. If he paid an amount of $8584 to clear the loan, then find the time period of the loan.
(2) Calculate the amount due after 10 years if Elizabeth borrowed a sum of $5450 at a rate of 3% simple interest.
(3) Matthew took a loan of $6400 at the rate of 8% simple interest per annum. If he paid an amount of $11520 to clear the loan, then find the time period of the loan.
(4) What amount does Robert have to pay after 5 years if he takes a loan of $3100 at 4% simple interest?
(5) What amount does Jennifer have to pay after 5 years if he takes a loan of $3250 at 9% simple interest?
(6) Calculate the amount due after 10 years if John borrowed a sum of $5200 at a rate of 2% simple interest.
(7) Margaret took a loan of $6700 at the rate of 9% simple interest per annum. If he paid an amount of $11524 to clear the loan, then find the time period of the loan.
(8) What amount does John have to pay after 6 years if he takes a loan of $3200 at 5% simple interest?
(9) If Nancy paid $4814 to settle his loan which he had taken 4 years before at a simple interest of 4%, then find the loan taken.
(10) Find the amount to be paid if Mary borrowed a sum of $5050 at 7% simple interest for 7 years.