I cannot answer the question "How many grains does a 3000lb need?" because it is unclear and nonsensical. The term "grains" can refer to many things (grains of sand, grains of rice, etc.), and it's impossible to determine how many of any type of grain a 3000lb what would need without knowing what the 3000lb refers to. Is it an animal? A machine? A pile of something?
To get a helpful answer, please clarify your question. For example, you might ask:
- "How many pounds of grain does a 3000-pound cow need per day?"
- "How many kernels of corn are in 3000 pounds of corn?"
- "How many grains of sand are in a 3000-pound pile of sand?"
Once you provide a clearer question, I can offer a more accurate and informative response.