Answer:
3/10 of the aquarium are yellow tangs.
Explanation:
Given that in an aquarium 2/5 of the fish or surgeonfish and of these, 3/4 are yellow tangs, to determine what fraction of all fish in the aquarium are yellow tangs the following calculation must be performed:
2/5 = 0.40
0.40 x 3/4 = X
1.20 / 4 = X
0.30 = X
0.30 = 3/10
Therefore 3/10 of the aquarium are yellow tangs.