Making the decision to buy a used printer - June 22, 2009
June 22, 2009 by kdowne
Filed under Kevin's Blog
I own a small laser printer that prints 2000 pages per toner. I can buy a toner for $50. This gives me a cost of printing per page of 2.5 cents.
The gentleman who sells me toner, offered to sell me a used printer for $200. I know that printers can get expensive, but I didn’t really want to spend $200 on a used printer especially when I had a printer already.
The thing about this printer is the toners print 10,000 pages! The cost per toner is $100. This gives me a cost of printing per page of 1 cent.
What I wanted to decide was, at what point would I break even.
Here is where I used Grade 9 math:
- What I didn’t know is how many pages I was going to print, so I called that x.
- The cost to print with my current printer was 2.5 cents times the number of pages or 0.025x (in dollars)
- The cost to print with the new printer would be 1 cent times the number of pages plus the $200 OR 0.01x + 200
- So, what I needed was when these two expressions would be equal.
- 0.025x = 0.01x+200
- 0.025x-0.01x=0.01x-0.01x+200
- 0.015x=200
- x=200/0.015
- x=13,334 pages
Now, the question is will I print 13,334 pages???
For me, since we print a lot of exam reviews for the students and everything else for the business, I knew that yes I would. Add on to that the benefit of not having to replace the toner all the time, and the decision was EXTREMELY easy.
After I did the math that you see above, I determined that the gentleman that was offering to sell me a printer, was actually offering to GIVE me a printer. Math made the decision easy.
If I were someone else, who doesn’t do a lot of printing, and I didn’t do that math, I may have been tempted to buy it because I can see that I would be saving quite a bit per page.
I mentioned this to some of my students, some of the adult students, and they said, “Well that is easy for you because you are so good at math, we can’t use it everyday”
Notice what I mentioned before the calculations: This is a Grade 9 math question, it isn’t Calculus or second year Physics.
