Question

Maki uses 20 gallons of a solution with an unknown ethanol concentration and 60 gallons of a 12% ethanol solution to make 80 gallons of a 10% solution. The table shows the amount of each solution.
What is the value of x, the concentration of the unknown ethanol solution?
a. 0.02
b. 0.04
c. 0.05
d. 0.08

Answer 1

b

Answer 2

how though?

Answer 3

i dont know how to explain it, sorry :(

Answer 4

are you sure it's b?

Answer 5

im 85% its b

Answer 6

Amount of ethanol in 20 gallons of unknown concentration = 20x
Amount of ethanol in 60 gallons of 12% solution = 60 * 0.12
Amount of ethanol in 80 gallons of 10% solution = 80 * 0.1
Now we can construct an equation as follows:
\[\large 20x+60\times0.12=80\times0.1\]
which simplifies to:
\[\large 20x+7.2=8\]

Answer 7

Now just solve the last equation to find the value of x.

Answer 8

so b?