Kenneth has 7 x 3 = <<7*3=21>>21 fish in his aquarium.

Matthias has 21 - 15 = <<21-15=6>>6 fish in his aquarium.

In total, the boys have 7 + 21 + 6 = <<7+21+6=34>>34 fish.

# Answer

34
<|im_start|>system
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<|im_start|>user
Micah has 7 fish in his aquarium. Kenneth has three times as many fish in his aquarium and Matthias has 15 less fish than Kenneth in his aquarium. How many fish do the boys have in total?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
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user
34
Micah has 7 fish in his aquarium. Kenneth has three times as many fish in his aquarium and Matthias has 15 less fish than Kenneth in his aquarium. How many fish do the boys have in total?
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