I am not so sure of this but I feel it would serve as hint
I want to say the answer is A i caulated it and i end up getting 17
Answer:
$ 0.8.
Step-by-step explanation:
1) if to assume, 'c' - price of the coffee and 'd' - price of the doughnuts, then
2) it is possible to write the equation 1 (when five MinB enter): 3d+5c=3.3;
3) it is possible to write the equation 2 (when three aliens entered): 4d+3c=2.75;

5) if c=0.45 and d=0.35, then Ag.Z. paid 0.35+0.45=$ 0.8.
Answer:
The mean is also increased by the constant k.
Step-by-step explanation:
Suppose that we have the set of N elements
{x₁, x₂, x₃, ..., xₙ}
The mean of this set is:
M = (x₁ + x₂ + x₃ + ... + xₙ)/N
Now if we increase each element of our set by a constant K, then our new set is:
{ (x₁ + k), (x₂ + k), ..., (xₙ + k)}
The mean of this set is:
M' = ( (x₁ + k) + (x₂ + k) + ... + (xₙ + k))/N
M' = (x₁ + x₂ + ... + xₙ + N*k)/N
We can rewrite this as:
M' = (x₁ + x₂ + ... + xₙ)/N + (k*N)/N
and (x₁ + x₂ + ... + xₙ)/N was the original mean, then:
M' = M + (k*N)/N
M' = M + k
Then if we increase all the elements by a constant k, the mean is also increased by the same constant k.