Anna bought 8 goldfish and 2 rainbow fish for her aquarium. the rainbow fish cost 6 dollars more than the goldfish. she paid a total of 37 dollars for the fish. write an equation to find the cost of each of the goldfish.

Let the price of the goldfish be x
Let the price of the rainbow fish be y

Anna bought 8 fish, therefore, Anna paid 8x for the gold fish
Anna bought 2 rainbow fish, therefore, Anna paid 2y for the rainbow fish

We know that the total amount that Anna paid is 37$.
Therefore:
8x + 2y = 37 > equation I

Now, we know that the rainbow fish cost 6$ more than the goldfish (since the verb "cost" is plural, therefore the total payment of rainbow fish is 6$ more than the total payment of gold fish).
Based on this,
2y + 6 = 8x 
2y = 8x - 6 > equation II

Substitute by equation II in equation I, we can get the following equation:
8x + 8x - 6 = 37 
16x = 43 > The desired equation (equation III)

Solving equation III, we can calculate the price of one gold fish as follows:
16x = 43
x = 2.6875$

If we substitute by the value of x in equation I, we can calculate the price of one rainbow fish as follows:
8(2.6875) + 2y = 37
y = 7.75$

The information we have is:

number of people = 120

number of females = 72.

number of people that purchase an ice cream = 41

number of males that purchase an ice cream = 36

First, for the total number of males in the theatre we can calculate the difference between the total number of poeple and the number of females:

Number of meales = 120 - 72 = 48

We also can calculate the number of females that buy an ice cream by the difference between the total number of people that buy an ice cream minus the number of males that buy an ice cream:

Number of females that purchase an ice cream = 41 - 36 = 5

now we can calculate the percentages as the number of a gender that does a given action divided the total number of individuals of that gender.

% of females that purchase ice cream = (5/72)*100% = 6%

% of males that purchase ice cream =  (36/48)*100% = 75%