Answer:
C
Step-by-step explanation:
Hope this helped! Please tell me if I'm wrong!
The 40 ml solution is said to be created from 10 ml and 30
ml solutions. In mixture problems, we equate the final mixture to its
compositions given the concentration for each. A 10 ml has 20% acid and the 30 ml has C
(unknown). We can write the total liters for 10 ml as 10(.2) and 30(c) for the
30 ml. when two solutions were added, it should be equal to 40ml with 32% acid.
Therefore, it should be written as 10(.2) + 30(c) = 40(.32). The answer is A
I think A, C, D are right because of the 12 pairs of heels, 6 are black (6/12) That means half of them could be chosen and be black (0.5). Another way to write 0.5 is as a percentage, 50%.
