A stick is 5 units long. It is broken at two points, chosen at random. What is the probability that all three pieces are longer than 1 unit?
Let the pieces be x, y and 5-(x+y)
y< -x+5, y>-x
Draw that up on a number plane and you get a triangle with an area of 12.5 that is your sample space.
Now graph the favourable area. And work out what it is.
You can take over from here.