00:01
This question has two parts.
00:03
In part a, we are asked to take a milliliter of butter and a milliliter of sand and we have to mix them together until we have two milliliters of stuff and we want to calculate the density.
00:18
So remember that butter has a density of 0 .860 grams and that's per milliliter.
00:32
And sand, according to this problem, is 2 .28 grams per one millimeter.
00:44
So if we're asked, as we are in this question, to take a milliliter of this and a millimeter of that, that means we're going to get 0 .860 grams of butter, and we're going to add to it 2 .28 grams of sand.
00:57
And if you do that, then you get 3 .14 grams in total, and that's divided by 2 milliliters.
01:07
And of course, if you simplify it, you get 1 .57 grams per milliliter.
01:15
And that's the answer to a there.
01:18
For b, it's a little trickier because rather than just having a milliliter of each of them, and if we know we have one milliliter of butter, we know that we bought 860 grams of butter.
01:29
But in this case, we're being told we are taking a gram of butter and a gram of sand.
01:36
And that means we have to figure out how much volume is involved...