# Math Help - Expected length?

1. ## Expected length?

Two points, X and Y , are chosen at random on a rod of length 1. What is the expected distance between these two points?

Can anyone help me out with this question? Not exactly sure where to start?

2. []EDIT[] $\color{red}{\text{Please delete.}}$

3. I think an easier approach is:

$E(|X-Y|) =\int \int |X-Y|f_{X,Y} dxdy$

Assuming......

$X$ ~ $\text{Uniform(0,1);}$ $Y$ ~ $\text{Uniform(0,1) i.i.d.}$

......makes this fairly simple, actually.