More Puzzles

More puzzles I found- these ones are used in job interviews at places like Microsoft, Boeing and IBM. Try one out...

1- If you have a fishbowl with 200 fish and 99 percent are guppies, how many guppies do you need to remove to get to the point where 98 percent of the remaining fish are guppies?

2- There are three ants at the three corners of a regular triangle. Each ant starts moving in a straight line toward another, randomly chosen corner. What is the probability that none of the ants collide?

3- Suppose you have eight billiard balls. One of them is defective -- it weighs more than the others. How do you tell, using a balance, which ball is defective in two weighings?