- #1
Michael805
- 5
- 0
Homework Statement
There are balls numbered 1 through n in a box. Suppose that a boy successively draws a ball from the box, each time replacing the one drawn before drawing another. This continues until the boy draws a ball that he has previously drawn before. Let X denote the number of draws, and compute its probability density function.
Homework Equations
Probability density function
The Attempt at a Solution
I was thinking at first this would simply be 1/n, but I'm unsure how to account for putting the ball back then calculating how many attempts it will take before drawing a previously drawn one.