Answer :
51 blue fish.
If there is 34 to 50 blue to red fish in tank A. Then tank B is 51 to 75. Because 75 is 1.5 times larger than 50 you have to multiply 34 by 1.5 to get 51.
If there is 34 to 50 blue to red fish in tank A. Then tank B is 51 to 75. Because 75 is 1.5 times larger than 50 you have to multiply 34 by 1.5 to get 51.