Solution of problem N2864 probability theory

Solution of problem N2864 probability theory

2864. In a group of 20 students - 9 are poorly performing. Two people are chosen at random from the group. What is the probability that among them: a) only one poorly performing student; b) at least one poorly performing student?

Additional information:

Detailed solution. Decorated in Microsoft Word 2003 (Quest decided to use the formula editor)

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