Answer:
18
Explanation:
Take a breath :) . I've got your back.
If she caught 6 carp + 8 bass + 7 catfish, she caught 6 +8 +7 fish total = 21.
7 of 21 were catfish.
If she catches 54 fish instead of 21, (and we have to assume the ratio stays the same), how many will be catfish?
Ratios are 7:21 and x:54, but we'll write them as fractions:
7/21 = x/54
Then cross multiply:
21x = (54)(7)
21x = 378
divide both sides by 21
x = 18
If she catches 54 fish total, we predict she will catch 18 catfish.
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If we go back to the original 7/21, we can reduce that to 1/3. Then ask what is 1/3 of 54? 18.