Word problems

Question

You need 455 mL of a 60% alcohol solution. On hand, you have a 65% alcohol mixture. How much of the 65% alcohol mixture and pure water will you need to obtain the desired solution?

You will need

________mL of pure water
and

________mL of the 65% solution.

Answer 1

X is the amount of 65 proof alcohol.

Y is the amount of water.

65% = 0.65;

60% = 0.60

 

X + Y = 455 mL

 

 

The amount of alcohol is 

  0.65X + 0*Y = 0.60*455

 

   0.65X = 273

 

   X = 420

 

420 mL of the 65 proof alcohol and 35 mL of water.