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32 votes
32 votes
You pick a card at random, put it back, and then pick another card at random. 6,7,8,9 What is the probability of picking a 9 and then picking an 8? Write your answer as a fraction or whole number.

User Stuart Mitchell
by
2.6k points

1 Answer

19 votes
19 votes

We have that the probability to pick the card with 9 is:


P(9)=(1)/(4)

then, the probability of picking the card with 8 is:


P(8)=(1)/(4)

since we are replacing the card after picking the first card, both events are independent, then, we have:


P(9\cap8)=P(9)\cdot P(8)=(1)/(4)\cdot(1)/(4)=(1)/(16)

therefore, the probability of picking a 9 and then picking an 8 is 1/16

User Whygee
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3.6k points
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