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put this solution on YOUR website!First, change the percents to decimals: 18% = 0.18, 50% = 0.5, 30% = 0.3
Now set up the necessary equation. Let x = the number of liters of 18% alcohol solution and (80 - x) = the number of liters of 50% alcohol solution.

Simplify and solve for x.

Subtract 40 from both sides.

Divide both sides by -0.32
The chemist will need 50 liters of the 18% alcohol solution and (80-50=30) 30 liters of the 50% alcohol solution to make 80 liters of 30% alcohol solution.