Darts on a ruler probability If two points are selected at random on an interval from 0 to 1.5 inches, what is
the probability that the distance between them is less than or equal to 1/4"?

I'm assuming the points are selected independently and using the uniform distribution on $[0, 1.5]$.  If you are unfamiliar with these terms you are probably assuming them implicitly and I wouldn't worry about it.  What I would do is draw a square 1.5 units on each side and draw the subset of the square of points $(x,y)$ with $|x-y| \leq 1/4$.  This region will be a hexagon.  Then divide the area of the hexagon by the area of the whole square.
Remark:
It looks like I am competing with another respondent!  I just read his suggestion, and I echo it: find the area of what is NOT in the hexagon, and subtract it from the square, instead of finding the area of the hexagon directly.  Since I stole from his answer, feel free to accept his instead of mine.
