there are 3 blue fish in the aquarium.
x = the number of red fish
y = the number of blue fish
x=y-1 is equation a
0.60(x+y)=y is equation b
substitute equation a in equation b and solve for y
y=3 blue fish
find the value of x
x=y-1 is x=3-1=2 red fish
this means that there are 3 blue fish in the aquarium.
2 red fish, 3 blue fish =5 fish total
20% for each fish, 20% x 5 =100%
2 red fish x 20%= 40%
3 blue fish x 20% =60%
answer is 3 blue fish
multiply 80 * 24, to get the total amount sold each day. divide by 10 to get the amount per hour.