Puzzle: Is the spider hungry?
A spider eats three flies a day. Until she has done this, she has an even chance of catching a fly that flies through her web. A fly is about to fly through the web. What is the fly’s chance of survival, given that today five flies have already flown through his web?
If you find this problem challenging, try it.
More below the fold: —> If you find this problem interesting, but not a real problem for you, here’s a challenge:
- Guess an approximate grade level that this problem is appropriate for, and
- Write a new problem, based on this one, but for a more advanced student, and then
- Write a new problem, based on this one, but for a less advanced student.
- Can you alter this one to create a nice problem to challenge high school math teachers?