How many gallons each of 25% alcohol and 10% alcohol should be mixed to obtain 15 gal of 12% 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 & 25%=0.25 & \\\hliney & 10%=0.1 & \\\hline 15 & 12%= & \\\hline\end{tabular}How many gallons of 25% alcohol should be in the mixture? □ gal
Q. How many gallons each of 25% alcohol and 10% alcohol should be mixed to obtain 15 gal of 12% 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 & 25%=0.25 & \\\hliney & 10%=0.1 & \\\hline 15 & 12%= & \\\hline\end{tabular}How many gallons of 25% alcohol should be in the mixture? □ gal
Define Variables: Let x be the gallons of 25% alcohol and y be the gallons of 10% alcohol. We know that x+y=15 because we want 15 gallons of the final mixture.
Calculate Total Alcohol: The total amount of pure alcohol in the final mixture should be 15 gallons times 12%, which is 15×0.12=1.8 gallons.
Alcohol Content Equation: The amount of pure alcohol in the 25% solution is 0.25x and in the 10% solution is 0.1y. So, the equation for the alcohol content is 0.25x+0.1y=1.8.
Solve System of Equations: We have two equations now: x+y=15 and 0.25x+0.1y=1.8. We can solve this system of equations by substitution or elimination. Let's use substitution.
Express y in terms of x: From the first equation, we can express y in terms of x: y=15−x.
Substitute y into Equation: Substitute y=15−x into the second equation: 0.25x+0.1(15−x)=1.8.
Solve for x: Now, let's solve for x: 0.25x+1.5−0.1x=1.8.
Combine Like Terms: Combine like terms: 0.15x+1.5=1.8.
Subtract 1.5: Subtract 1.5 from both sides: 0.15x=0.3.
Divide to Find x: Divide by 0.15 to find x: x=0.150.3.
More problems from Weighted averages: word problems