So this is basically a ratio and the form I use to solve these is
Is. = %
Of. 100
So we're looking for 5% of the 350,000 which will be x
X. = 5
350000. 100
Cross multiply
100x=1750000
Divide by 100
X=17500
X/y = 2 so x = 2y
z/x = 4 so z = 4x but x = 2y so z = 4(2y) = 8y
now you have
x = 2y, z = 8y
x + y + z 2y + y + 8y 11y 11
------------ = -----------------------= ------------- = ----------- = 5 1/2
x 2y 2y 2
answer
C. 5 1/2
Domain = Set of all real numbers, which is choice B
Range = Choice C)

The domain is the set of allowed x value inputs of a function. In this case, we can plug in any x value we want. The graph stretches forever in both directions along the x axis. This is shown by the arrows.So that's why the domain is the set of all real numbers.
The range is the set of outputs of a function. It is the set of possible y values. As you can see on the graph, the highest point is at (-1,3) which is the vertex.
The largest y value possible is y = 3. Any other y value smaller than this is possible. So the range is therefore

where y is a real number