+8 is the greatest then -8
The answer is B.
14 + 15x
14 + 15(5)
14 + 75
89
Surface of a cubical box=6(side²)
1)We have to calculate the surface of this cubical box.
Rate=cost of painting / surface ⇒surface=cost of painting/rate
Data:
Rate=$15/m²
cost of painting=$1440
Surface=$1440/($15/m²)=96 m²
2)We find out the length of the side:
Surface of a cubical box=6(side²)
Data:
Surface of a cubical box=96 m2
Therefore:
96m²=6 (side²)
side²=96 m²/6
side²=16 m²
side=√(16 m²)=4 m
3) We find the volume of a cubical box.
volume=(side³)
volume=(4 m)³
volume=64 m³
Answer: the volume of this cubical box would be 64 m³.
Answer: choice A. 40 liters
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Explanation:
x = number of liters of the 50% alcohol solution
If we have x liters of 50% alcohol, then we have 0.50*x liters of pure alcohol. This is added to 0.90*40 = 36 liters of pure alcohol (from the 90% solution).
So far we have 0.50*x + 36. This expression represents the total amount of pure alcohol. We want a 70% solution, so we want 70% of the total 40+x meaning 0.50*x + 36 is to be set equal to 0.70*(40+x) and we solve for x as shown below
0.50*x + 36 = 0.70*(40+x)
0.50*x + 36 = 0.70*(40)+0.70*(x)
0.50*x + 36 = 28+0.70*x
36 - 28 = 0.70*x - 0.50x
8 = 0.20x
0.20x = 8
x = 8/0.20
x = 40
So that is why the answer is choice A. 40 liters
