Question

There is a stack of 10 cards, each given a different number from 1 to 10. Suppose we select a card randomly from the stack, replace it, and then randomly select another card. What is the probability that the first card is an odd number and the second card is greater than 6? Write your answer as a fraction in simplest form

Answer 1

Sample space={1,2,3,4,5,6,7,8,9,10} = 10 total outcomes

a) Favorable odds number = {1,3,5,7,9} = 5 favorable outcomes
b) Favorable > 6 = {7,8,9,10} = 4 favorable outcomes

P(drawing ODD) = 5/10 = 1/2
P(drawing >6) = 4/10 = 2/5

P(drawing odd AND > 6) = P( odd ∩ > 6) = (1/2).(2/5) = 2/10 = 1/5

And P( odd ∩ > 6) = 0.2