there are 10 people sitting in a room. 3 are friends. what is the posibility of 1 of the friends coming out of the room and then the next friend?
Last edited by ketanco; Nov 19th 2018 at 12:13 AM.
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$P[\text{2 friends are first two out of room}] = \dfrac{3}{10}\dfrac{2}{9} = \dfrac{6}{90}=\dfrac{1}{15}$