How many gallons each of 30% alcohol and 10% alcohol should be mixed to obtain 20 gal of 15% alcohol?\begin{tabular}{|c|c|c|}\hline \begin{tabular}{c} Gallons of \\Solution\end{tabular} & \begin{tabular}{c} Percent \\(as a decimal)\end{tabular} & \begin{tabular}{c} Gallons of \\Pure \\Alcohol\end{tabular} \\\hlinex & 30%=0.3 & \\\hliney & 10%=0.1 & \\\hline 20 & 15%= & \\\hline\end{tabular}How many gallons of 30% alcohol should be in the mixture? □ galHow many gallons of 10% alcohol should be in the mixture? □ gal
Q. How many gallons each of 30% alcohol and 10% alcohol should be mixed to obtain 20 gal of 15% alcohol?\begin{tabular}{|c|c|c|}\hline \begin{tabular}{c} Gallons of \\Solution\end{tabular} & \begin{tabular}{c} Percent \\(as a decimal)\end{tabular} & \begin{tabular}{c} Gallons of \\Pure \\Alcohol\end{tabular} \\\hlinex & 30%=0.3 & \\\hliney & 10%=0.1 & \\\hline 20 & 15%= & \\\hline\end{tabular}How many gallons of 30% alcohol should be in the mixture? □ galHow many gallons of 10% alcohol should be in the mixture? □ gal
Define variables: Let x be the gallons of 30% alcohol, and y be the gallons of 10% alcohol.
Total volume equation: The total volume of the mixture should be 20 gallons, so x+y=20.
Total alcohol amount: The total amount of pure alcohol in the mixture should be 15% of 20 gallons, so 0.15×20=3 gallons.
Alcohol content equations: The amount of pure alcohol in the 30% solution is 0.3x and in the 10% solution is 0.1y.
Combine equations: The sum of pure alcohol from both solutions should equal the total pure alcohol in the mixture: 0.3x+0.1y=3.
Substitute and simplify: Now we have two equations: x+y=20 and 0.3x+0.1y=3.
Solve for x: Solve the first equation for y: y=20−x.
Solve for x: Solve the first equation for y: y=20−x.Substitute y in the second equation: 0.3x+0.1(20−x)=3.
Solve for x: Solve the first equation for y: y=20−x. Substitute y in the second equation: 0.3x+0.1(20−x)=3. Distribute and combine like terms: 0.3x+2−0.1x=3.
Solve for x: Solve the first equation for y: y=20−x. Substitute y in the second equation: 0.3x+0.1(20−x)=3. Distribute and combine like terms: 0.3x+2−0.1x=3. Combine x terms: 0.2x+2=3.
Solve for x: Solve the first equation for y: y=20−x.Substitute y in the second equation: 0.3x+0.1(20−x)=3.Distribute and combine like terms: 0.3x+2−0.1x=3.Combine x terms: 0.2x+2=3.Subtract 2 from both sides: 0.2x=1.
Solve for x: Solve the first equation for y: y=20−x. Substitute y in the second equation: 0.3x+0.1(20−x)=3. Distribute and combine like terms: 0.3x+2−0.1x=3. Combine x terms: 0.2x+2=3. Subtract 2 from both sides: 0.2x=1. Divide by 0.2 to solve for x: y0.
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