There are 20 students in a class. 12 are girls, 8 are boys. 3 girls like to play softball, 4 boys like to play softball. Find the probability of picking two students from the class and choosing a girl or a softball player. Explain your work.

Question

anonymous · Answer

Girls 12/20    and Softball Players: 7/20

anonymous · Answer

Since this is a dependent event, shouldn't I multiply both 12/20 and 7/20 to get 21/100?

anonymous · Answer

A = choosing a girl     B = choosing a softball player
since they are not mutually exclusive events:
P(AorB) = P(A) + P(B) - P(AandB) 
            = P(A) + P(B) - P(A)P(B)

phi · Answer

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