Let 'a' be the number of ounces of 2%-solution in the 25-ounce mixture
and 'b' be the number of ounces of 5%-solution in the 25-ounce mixture.
Since, fluid ounces of each concentration should be combined to make 25 fl oz.
So, a+b=25 (Equation 1)
And, a container of 2% acid solution and a container of 5% acid solution should be combined to make 25 fl oz of 3.2% acid solution.
So, a of 2% + b of 5% = 3.2% of 25


Multiplying the above equation by 100, we get
(Equation 2)
Substituting the value of a=25-b in equation 2, we get





Since, a=25-b
a= 25-10
a=15.
So, 15 fluid ounces of 2% solution combined with 10 ounces of the 5% solution to create a 25-ounce mixture at 3.2% concentration of acid.
2.
You will have on real root, and two complex which derives from the 3rd degree polynomial function.
When you expand the binomial, you isolate each of the parts.
So, (x-y)^4 would turn into...
x^4 - y^4
The powers stay the same because (outside the parenthesis) you multiply them with whatever is inside the parenthesis. In this case, would be 1. All variables and numbers without a listed power have a power of one. Multiply 4*1 to get 4.
Between the probability of union and intersection, it's not clear what you're supposed to compute. (I would guess it's the probability of union.) But we do know that

For parts (a) and (b), you're given everything you need to determine

.
For part (c), if

and

are mutually exclusive, then

, so

. If the given probability is

, then you can find

. But if this given probability is for the intersection, finding

is impossible.
For part (d), if

and

are independent, then

.
Answer:
D
Step-by-step explanation:
You would do D because the other options aren't that random. Randomly choosing employees <em>is</em> a random sample and will give you a valid answer.