Answer:
300ml
Step-by-step explanation:
As values are missing in your question, the complete question is:
In the lab, Leila has two solutions that contain alcohol and is mixing them with each other. Solution A is 6% alcohol and Solution B is 20% alcohol. She uses 400 milliliters of Solution A. How many milliliters of Solution B does she use, if the resulting mixture is a 12% alcohol solution?
Considering x=ml of 20% solution B
Therefore, 400+x=ml of resulting 12% solution
Solution A alcohol+ solution B alcohol= Alcohol solution
6% (400)+ 20%x = 12%(400+x) ->(converting percentage into decimal)
.06*400+.2x=.12(400+x)
24+.2x=48+.12x
.08x=24
x=24/.08=300 ml
she used 300 milliliters of 20%Solution B in resulting mixture.
