Lizzy: There's a Bobbit worm hiding in the bottom of James' aquarium. Every day it eats 2 fish. After two weeks, James adds 8 more fish to the aquarium. A week later, he discovers the Bobbit worm. If the aquarium had 60 fish to start with, how many does it have when James discovers the Bobbit worm?.
Me: Hmmm, let me think. I think this is the detailed solution:
First find the total number of weeks the Bobbit worm preys on the fish: 2 weeks + 1 week = 3 weeks. Then multiply that number by the number of days per week: 3 weeks * 7 days / week = 21 days. Then multiply that number by the number of fish the worm eats per day to find how many fish it eats total: 21 days * 2 fish / day = 42 fish. Then add the number of fish James adds to the starting number of fish to find the ending number of fish: 60 fish + 8 fish = 68 fish. Then subtract the number of eaten fish to find the number of surviving fish: 68 fish - 42 fish = 26 fish. Final answer: 26.