In the Tide Pool tank at the Atlantic Aquarium, there are 10 crustaceans and 25 fish. The Deep Blue tank has the same ratio of crustaceans to fish. There are 50 crustaceans in the Deep Blue tank.

How many fish are in the Deep Blue tank?
fish

Since the ratio of crustaceans to fish is the same in both tanks, we can set up the following equation:

10 crustaceans / 25 fish = 50 crustaceans / x fish.
To solve for x, we cross-multiply and then divide:
10x = 50 * 25
10x = 1250
x = 1250 / 10
x = <<1250/10=125>>125.
Therefore, there are 125 fish in the Deep Blue tank.