Topic: Choosing ping-pong balls without replacement.

There are 5 white and 4 orange ping-pong balls in a brown paper bag. Two balls are randomly chosen.

Enter your answers as fractions. They do not need to be reduced.

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a) How many total balls are in the bag at the start?

b) What is the probability that the 1st ball is orange?

P(1st = orange) =

c) What is the probability that the 2nd ball is also orange, given that the 1st ball was orange?

P(2nd = orange | 1st = orange) =

d) What is the probability that both the 1st and the 2nd balls are orange?