Sam's two new aquariums each hold exactly 200 gallons of water. one aquarium will hold small fish and the other will hold large fish. now he needs new fish for his aquarium. he will buy 5 small fish for every 10 gallons of water in the aquarium. he will buy 8 large fish for every 40 gallons of water in the aquarium. what is the total number of fish sam will have? what will be the ratio of sam's small fish to large fish? and to anyone who tried and gave me the best answer you could (:

Aquarium 1 will hold 5 small fish for every 10 gallons of water. If there are 200 gallons in the tank, you can sent up a proportion:
5 small fish/10 gallons = x small fish/ 200 gallons
if you cross multiply, you get 
10x = 200 × 5
10x = 1000
x = 100 
100 small fish will be in 200 gallons of water. 

Aquarium 2 will hold 8 large fish for every 40 gallons of water. A proportion can also be set up here: 
8 large fish/ 40 gallons = x large fish/ 200 gallons
if you cross multiply, you get: 
40x = 200 × 8 
40x = 1600
x = 40 
40 large fish will be in 200 gallons of water. 

the ratio of small fish to large fish:
100 small fish: 40 large fish
(both are divisible for 10, and if you divide both of them by ten you get)
10 small fish: 4 large fish
you can reduce again, since both are divisble by 2
5 small fish: 2 large fish