00:01
Okay, we are told that we're going to mix two alloys together plus some of a metal x to make a new alloy.
00:07
So we are told we have two metals.
00:11
We have metal x and metal y.
00:16
So if we're doing a ratio of x to y, alloy number one has a six to five ratio.
00:28
Alloy number two has a seven to 13 ratio.
00:34
So just to interpret that, what that means, and because it's a ratio to weight, what that means is for every 6kg of x will have 5 kilograms of y.
00:53
For every 7 kilograms of x, we will have 13 kilograms of y.
01:01
We are told we're going to mix or use 11 kilograms of alloy 1.
01:15
20 kilograms of alloy 2, and we're told we have an unknown amount of x that we're going to add together.
01:26
We are told that we have to figure out what x is.
01:29
So we know that the total mass of the new alloy would be 11 plus 20, which would be 31 kilograms, plus whatever we add of x extra, besides what's in alloy number one.
01:52
And 2.
01:53
We are told the percent of y must be 40 percent.
02:00
And we find the percent of y by taking the amount of y, divided by the total, which we just said was 31 plus x, and we'd multiply it by a hundred to make it a percent.
02:15
So that is our formula for percent of y.
02:19
So we need to figure out how much of y we used.
02:23
And the nice thing we were told is in alloy one, we used 11 kilograms.
02:28
And since 6 plus 5 is 11, that means edit that there, we use 6 kilograms of x and we use 5 kilograms of y...