probability of picking a number under 100 I have a set of 100 numbers (from 1 to 100), from which a selector randomly picks numbers. What is the probability, that the selector will pick numbers under 95 (equal or less) three times consecutive?

I assume the obvious that the selector picks numbers with equal probability (or chances); also that it leaves those numbers there for the next pick. You essentially want it to pick one of the first 95 out of the 100 numbers. This gives you the selector's chances for one pick. Then you want it to do it 3 times in a row. 
Maybe you know a similar example you can use: if you throw a coin and you know the probability of getting heads once, what is the probability of getting heads twice? This is easy to compute because you can count all the possible events for 2 throws. Think about 3 throws. You'll see how the probability for 1 pick gives the probability of 3 independent picks.
