###Human: Will and Henry go fishing in a river. Will catches 16 catfish and 10 eels. Henry challenges himself to catch 3 trout for every catfish Will catches. Due to environmental concerns, Henry decides to return half his catch after meeting his own challenge. How many fishes do they have altogether now?, ### Assistant: Will caught 16+10= 26 fishes
Henry caught 3 trout for each catfish Will caught so since Will caught 16 catfish, Henry caught 16*3 = 48 trout
Half of 48 trout is (1/2)*48 = 24
Henry returned 24 trout leaving him with 48-24 = 24 trout
They now have a total of 26+24 = 50 fishes 
 So the answer is :  50