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:
16
Step-by-step explanation:
3 |a-b| +2|b-1|
a= -2 and b=-4
3 |-2--4| +2|-4-1|
3 |-2+4| +2|-4-1|
3 |2| +2|-5|
Absolute value means takes whatever is inside and make it positive
3*2 +2*5
6 +10
16
Answer:
A
Step-by-step explanation:
Sales tax is a certain percent of a bill that is taken and sent to the state. Example: Florida sales tax is 7% of the total.
