Question:
Calculate the amount due after 9 years if John borrowed a sum of $5200 at a rate of 3% simple interest.
Correct Answer
$6604
Solution And Explanation
Solution
Given,
Principal (P) = $5200
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) = $5200 × 3% × 9
= $5200 ×3/100 × 9
= 5200 × 3 × 9/100
= 15600 × 9/100
= 140400/100
= $1404
Thus, Simple Interest = $1404
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 = $5200 + $1404
= $6604
Thus, Amount to be paid = $6604 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 = $5200
Rate of Simple Interest (SI) or (R) = 3%
And, Time (t) = 9 years
Thus, Amount (A)
= $5200 + ($5200 × 3% × 9)
= $5200 + ($5200 ×3/100 × 9)
= $5200 + (5200 × 3 × 9/100)
= $5200 + (15600 × 9/100)
= $5200 + (140400/100)
= $5200 + $1404 = $6604
Thus, Amount (A) to be paid = $6604 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 $5200, the simple interest in 1 year
= 3/100 × 5200
= 3 × 5200/100
= 15600/100 = $156
Thus, simple interest for 1 year = $156
Therefore, simple interest for 9 years
= Simple interest for 1 year × 9
= $156 × 9 = $1404
Thus, Simple Interest (SI) = $1404
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $5200 + $1404
= $6604
Thus, Amount to be paid = $6604 Answer
Similar Questions
(1) Find the amount to be paid if Michael borrowed a sum of $5300 at 7% simple interest for 7 years.
(2) In how much time a principal of $3000 will amount to $3750 at a simple interest of 5% per annum?
(3) Calculate the amount due if Sarah borrowed a sum of $3850 at 2% simple interest for 3 years.
(4) Find the amount to be paid if Joseph borrowed a sum of $5700 at 2% simple interest for 8 years.
(5) What amount does Christopher have to pay after 6 years if he takes a loan of $4000 at 5% simple interest?
(6) Calculate the amount due if Patricia borrowed a sum of $3150 at 7% simple interest for 4 years.
(7) Calculate the amount due if Elizabeth borrowed a sum of $3450 at 10% simple interest for 3 years.
(8) Find the amount to be paid if Joseph borrowed a sum of $5700 at 9% simple interest for 7 years.
(9) If Mary borrowed $3050 from a bank at a rate of 3% simple interest per annum then find the amount to be paid after 2 years.
(10) Calculate the amount due after 9 years if John borrowed a sum of $5200 at a rate of 9% simple interest.