Answer:
Male Fish = 20
Female Fish = 16
Step-by-step explanation:
Let number of male fish be x and number of female fish be y
There are 36 fishes in total, so we can write:
x + y = 36
or
x = 36 - y
Also, male fish (x) cost 5 each and female fish (y) cost 7 each totalling $212, so we can write:
5x + 7y = 212
Now, we can put 1st equation in 2nd equation and get an equation in "y" and solve for y first:
We know x = 36 - y, so
x = 36 - 16
x = 20
Thus,
there are
20 Male fishes & 16 female fishes in the aquarium