Your answer is E. $25.
First let under 12 = u, over 12 = o, and adults = a.
We can now write the equations:
2u + 3a + 3o = 174
4u + 2a = 122
a + o = 46
Because we know that a + o = 46, and 3a + 3o is in the first equation, we can multiply 46 by 3 to get what 3a + 3o equals. This makes 138.
Now we can substitute 138 into the first equation to get 2u + 138 = 174
2u = 36
u = 18
Now that we know what u equals, we can substitute it in to the second equation to get:
4(18) + 2a = 122
72 + 2a = 122
2a = 50
a = $25
I hope this helps! Let me know if you have any questions :)
Step-by-step explanation:
The given objective function is 
To check that which ordered pair is minimizing the objective function-we will substitute all the ordered pair one by one in the given function and we will calculate the value of C. The ordered pair which will give the minimum value will be the answer.
For (0, 160)

For (55, 70)

For (80, 50)

For (80, 50)

Hence the ordered pair which minimizes the objective function is (80, 50)
That would be written as:

And the step-by-step equation would be:
→ we take the 2 to the right side of the equation and do the IO*
→we solve for 
→ final answer
*Ps - IO is not an existing term and stands for inverse operation. In this case, because when we take to 2 to the right side of the equation (the 2 is a power) it'll have to turn into a square root (because exponents and roots are inverse operations)
Hope it helped,
BioTeacher101
Lets split the box in pieces and then add:
top = 20*15 = 300
sidesA = 2*20*9 = 360, is multiplied by 2 cause there are 2 sides like this
sidesB = 2*9*15 = 270, is multiplied by 2 cause there are 2 sides like this
so in total we have:
total = 300 + 360 + 270 = 930 cm^2
if we express this quantity in mm^2 we have:
<span>1cm² = 100 mm²</span>total = 930*100 = 93000 mm^2
so if the tiles are 5 mm^2 we need:
total tiles = <span>93000/5 = 18600
we need 18600 tiles of 5 mm^2</span>