Question

11. Your computer supply store sells two types of laser printers. The first type, A, has a cost of $86 and you make a $45 profit on each one. The second type, B, has a cost of $130 and you make a $35 profit on each one. You expect to sell at least 100 laser printers this month and you need to make at least $3850 profit on them. How many of what type of printer should you order if you want to minimize your cost?

Answer 1

You need 2 inequalities to solve this, one based on the NUMBER of printers and one based on MONEY. You will sell at least 100 printers, so your first inequality would be A+B>=100 (that's greater than or equal to). The second is based on the profit earned from each because the question in the end wants you to find how many you need to sell of each to make a profit of at least 3850. So the second inequality looks like this: 45A+35B>=3850. Solve the first inequality for A: A=100-B. Now sub this new A into the second inequality to get 45(100-B)+35B>=3850. Distribute to get 4500-45B+35B>=3850. Do the math to get that you need to sell 65 of B and 35 of A