Step-by-step explanation:
(Explanation is above)
So... let's change the concentration percentage to decimal format. .. so 40% is just 4/100 or 0.4 and so on.

so... whatever "x" and "y" may be, we know the must add up to 6 liters.
and whatever 0.4x and 0.8y are, we also know, they must add up to a 3 of concentrated amount.
thus

solve for "x", to see how much of the 40% solution will be needed.
what about "y"? well, y = 6 - x.
8 (4 sessions from each gym)
Answer:
237
Step-by-step explanation:
63 / .21 = 300
300 total people on list
21 percent are electronic so 79 percent are not electronic
300 x .79 = 237
Answer:14 cubic units
Step-by-step explanation: