166,416 views
8 votes
8 votes
You pick a card at random, put it back, and then pick another card at random.

4 5 6 7
What is the probability of picking a 7 and then picking an odd number?
Simplify your answer and write it as a fraction or whole number.

User Velimir Tchatchevsky
by
2.7k points

1 Answer

16 votes
16 votes

Answer: 1/8

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Step-by-step explanation:

A = probability of picking a 7

A = 1/4 since one card is labeled "7" out of four cards total

B = probability of picking an odd number

B = 2/4 = 1/2 because there are 2 cards that are odd (5 and 7) out of 4 cards total.

C = A*B = probability events A and B happen

C = (1/4)*(1/2)

C = 1/8

This only works when we put the first card back, which means each event is independent.

User Aleung
by
2.7k points
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