Bobby has an aquarium with twice as many fish as Sarah's has. Sarah has 5 more fish in her aquarium than Tony does. Tony has 3 times as many fish in his aquarium as Billy does. Billy has 10 fish. How many fish do all 4 people have put together?
Thoughts? Step-by-step reasoning:
Since Tony has 3 times as many fish as Billy's 10, that means Tony has 3 * 10 = 30 fish. Sarah has 5 more fish than Tony's 30, meaning she has 5 + 30 = 35 fish. Bobby has twice as many fish as Sarah does, meaning he has 35 * 2 = 70 fish. Therefore, altogether there are 10 + 30 + 35 + 70 = 145 fish.
Thus, the answer is 145.