My question is: Bill is trying to control the pests in his garden. Each spider he introduces eats 7 bugs, and each time he sprays the garden he reduces the total bug population to 80% of what it was previously. If the garden has 400 bugs to start, and Bill sprays once and introduces 12 spiders, how many bugs are left? Your thoughts:
First find the total bug population after spraying: 80% * 400 bugs = 320 bugs. Then find the total number of bugs each spider eats: 12 spiders * 7 bugs / spider = 84 bugs. Then subtract that number from the number of bugs left after spraying to find final number of bugs: 320 bugs - 84 bugs = 236 bugs. The final answer: 236.