Question

In the lab, Martina has two solutions that contain alcohol and is mixing them with each other. Solution A is  

40% alcohol and Solution B is 12% alcohol. She uses 1000 milliliters of Solution A. How many milliliters of Solution B does she use, if the resulting mixture is a 32%

alcohol solution?

Answer 1

Let volume of B in mixture be x

THus total volume= (1000+ x)mL

But this total volume of mixture contains 32% of alcohol i.e. (1000+ x)* 32/100 mL

Solution A is 40 % alcohol

THu, 1000 mL of solution A in mixture contains 1000*40/100 =400 mL of alchol

Similarly, x mL of solution B contains x*12/100 = 12x/100= 0.12 x mL of alcohol

So, 400mL +  0.12 x mL = (1000+ x)* 32/100 mL

400 +0.12 x = 320 + 0.32 x

80 mL = 0.20 x

x = 400mL

Thus, Volume of B in mixture is 400 mL