 So in the lab, we're going to be working with blue dye, a blue dye solution, and blue dye is normally used to color foods. So if you got a task to make up 10 mils of a 1 in 36 blue dye solution, how do you do that? So actually the way of writing the dilution is actually 1 over 36. So if you're going to make a solution that has this concentration, what you want to do is to add one part of your stock blue dye. So your stock blue dye solution is your undiluted blue dye solution. So that is one part of stock blue dye solution, or I should say not solution, it's the solvent, the solute would be the blue dye. And you're going to add this to 35 parts of distilled water. So I can determine, I just want to make 10 mils of solution though. So what I need to determine is if one mil of stock dye gives me 36 mils of blue dye solution when I dilute it in 35 mils of water, how much dye will I need to make 10 mils of solution? And from your class you probably know how to work out this particular problem. What you would do is to do what is called cross multiplication. So you arrange your equation so that your question mark is on one side. And in that case you're going to multiply your 10 mils by your 1 mil of stock dye. So what you'd have here is 1 times 10 divided by 36. And this will tell you how much of your solution, how much of the stock dye you would need to make your 1 in 36 solution. So in this case you need 0.28 mils of stock dye. So if you recall we're adding the dye, the stock dye, to water. But this is just telling you the part where you're adding one part of stock dye solution, solute. So you have to figure out what the 35 parts of distilled water is. So remember your final volume is 10 mils. So that means you're going to be making up 10 minus 0.28 mils of stock dye. And that would tell you that you're going to add 9.72 mils of water to your stock dye solute to give you 10 mils of solution. So that is how you would make your 1 in 36 blue dye solution. This is basically how you make up your simple dilution, you make up your solution using the simple dilution method.