Question:
Calculate the amount due if James borrowed a sum of $3000 at 9% simple interest for 3 years.
Correct Answer
$3810
Solution And Explanation
Solution
Given,
Principal (P) = $3000
Rate of Simple Interest (SI) = 9%
Time (t) = 3 years
Thus, Amount (A) = ?
The Rate of Interest is always calculated per annum, i.e. per year.
Thus, here 9% simple interest means, Rate of Simple Interest (SI) is 9% 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) = $3000 × 9% × 3
= $3000 ×9/100 × 3
= 3000 × 9 × 3/100
= 27000 × 3/100
= 81000/100
= $810
Thus, Simple Interest = $810
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 = $3000 + $810
= $3810
Thus, Amount to be paid = $3810 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 = $3000
Rate of Simple Interest (SI) or (R) = 9%
And, Time (t) = 3 years
Thus, Amount (A)
= $3000 + ($3000 × 9% × 3)
= $3000 + ($3000 ×9/100 × 3)
= $3000 + (3000 × 9 × 3/100)
= $3000 + (27000 × 3/100)
= $3000 + (81000/100)
= $3000 + $810 = $3810
Thus, Amount (A) to be paid = $3810 Answer
Method (3) Unitary Method
Calculation of Amount using Unitary Method
Calculation of Interest using Unitary Method
Here, given Rate of Simple Interest = 9%
This, means, $9 per $100 per year
∵ For $100, the simple interest for 1 year = $9
∴ For $1, the simple interest for 1 year = 9/100
∴ For $3000, the simple interest in 1 year
= 9/100 × 3000
= 9 × 3000/100
= 27000/100 = $270
Thus, simple interest for 1 year = $270
Therefore, simple interest for 3 years
= Simple interest for 1 year × 3
= $270 × 3 = $810
Thus, Simple Interest (SI) = $810
Calculation of Amount
Amount = Principal + Interest
Thus, Amount = $3000 + $810
= $3810
Thus, Amount to be paid = $3810 Answer
Similar Questions
(1) Find the amount to be paid if Barbara borrowed a sum of $5550 at 6% simple interest for 7 years.
(2) What amount does Michael have to pay after 6 years if he takes a loan of $3300 at 8% simple interest?
(3) What amount will be due after 2 years if Matthew borrowed a sum of $3600 at a 7% simple interest?
(4) What amount will be due after 2 years if David borrowed a sum of $3200 at a 6% simple interest?
(5) Find the amount to be paid if Barbara borrowed a sum of $5550 at 10% simple interest for 8 years.
(6) Calculate the amount due if Jessica borrowed a sum of $3750 at 4% simple interest for 4 years.
(7) Calculate the amount due if Barbara borrowed a sum of $3550 at 10% simple interest for 4 years.
(8) Find the amount to be paid if Linda borrowed a sum of $5350 at 4% simple interest for 7 years.
(9) Calculate the amount due after 10 years if John borrowed a sum of $5200 at a rate of 8% simple interest.
(10) How much loan did Thomas borrow 5 years ago at a rate of simple interest 5% per annum, if he paid $7250 to clear it?