Alemayehu S. answered 12/08/14
Tutor
New to Wyzant
Passionate and Patient Biology grad, well-versed in SAT/GRE prep
For this, it is best to look at the problem from a business standpoint. That is, what is my initial cost and what is my profit.
Initial cost here is 864. Easy.
Initial profit takes one calculation. If it costs .80 dollars to package a book (think of the materials involved), yet you sell the book for 2.00 dollars, you are making 2-.8 = $1.20 dollars profit per book sold.
Now, you can write an equation that demonstrates this. let b = number of books sold here:
1.2b-864 = 0
Note how I subtracted 864. Why? Well, first of all, 1.2 and 864 are both the same unit (dollars), so we can do that and we do not have to convert. Second, that is your start-up cost. So no matter how much you make, you have to take it into account when you are calculating the answer. Now, solve for b:
1.2b = 864
b = 864/1.2
b = 720
So, you would need to sell 720 books to break even. 721+ books is where you would start making a profit.