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
Answer:
See below
Step-by-step explanation:
To begin, it is volume, not area
1. 8 x 12 x 17 = 1632 in ^3
5. 9 x 9 x 13.5 = 1093.5 in^3
If you want to find SURFACE AREA:
1. 2(8 x 12) + 2(8 x 17) + 2(17 x 12) = 872 in^2
5. 2(9 x 9) + 4(9 x 17) = 774 in^2
Which color do most children like best? ask 10 children make tally mark for each child's answer
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Step-by-step explanation:
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