Answer:
465
Step-by-step explanation:
Since we are looking for the the number of combinations to have 2 different flavors in the ice cream, we can use the formula for combination.

Our variables are:
n = 31
k = 2




The number of possible combinations of having 2 different flavors out of 31 different flavors is 465.
Answer:

Step-by-step explanation:
Given
y jointly varies to x and z^2
Required
Find the equation
We start by writing out the variation;

Write as equation

Substitute values of x,y and z



Divide both sides by 7




Substitute k in 

The greatest number of copies you can et for three dollars is 24.