A point is selected at random on a line segment of length $l$.
What is the probability that none of the two segments is smaller than $\frac{l}{3}$?
Progress: Let $X$ = length of the segments
$X$~ U[$0,l$]
$f_X(x)$ = $\frac{1}{x}$ $0 \leq x \leq l$
And we need P($\frac{l}{3} \leq x \leq \frac{2l}{3}$). How do I find this probability?