What is the probability that three randomly drawn real numbers between 0 and 1 have a sum less than 1? Express your answer as a common fraction.
https://www.mathcounts.org/resources/video-library/mathcounts-minis/mini-87-using-geometric-models-determine-probability
Follow the link and a guy that looks like will explain it to ya.
Thanks for showing us that clip KnockOut.
I learned from it.