Links
[1] https://www.hootsgo.org/?q=node/6719
[2] http://www.cut-the-knot.org/Probability/IndependentEvents.shtml
[3] http://www.cut-the-knot.org/Curriculum/Probability/ConditionalProbability.shtml
[4] http://www.cut-the-knot.org/Probability/MutuallyIndependentEvents.shtml
[5] http://www.cut-the-knot.org/Probability/IndependentExperiments.shtml