Plz help ASAP with explanation

The height of the tank in the picture is:

Step-by-step explanation:

First, to know the height of the tank, we're gonna change the unit of the volume given in liters to cm^3:

So:

Now, we must calculate the height of the tank that we don't know (the other part that isn't with water), to this, we can use the volume formula clearing the height:

Now, we must clear the height because we know the volume (1200 cm^3):

Height = volume of a cube / (long * wide)

And we replace:

Remember this is the height of the empty zone, by this reason, to obtain the height of the whole tank, we must add the height of the zone with water (7 cm) that the exercise give us:

In this form, we calculate the height of the tank in 19.5 cm.

stops on an even number.

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional