Question

1. Ten slips of paper labeled from 1 to 10 are placed in a hat. The first slip of paper is NOT replaced before selecting the second slip of paper. What is the probability of selecting and odd number and then a number greater than 9? 1/2 1/18 6/10 3/25
2. The probability of drawing two white cards without replacement is 14/95, and the probability of drawing one white card is 2/5. What is the probability of drawing a second white card, given that the first card is white? 52/95 7/19 7/38 28/475
3. Kim rolls a 6-sided number cube. What is the probability she rolls a number greater than 3 or a 1? 2/3 1/2 1/12 1/3

Answer 1

1. If we get an odd number first (probability 5/10 = 1/2), then the only way to get a number greater than 9 is the 10 (probability 1/9, since only 9 papers remain). This gives 1/2 * 1/9 = 1/18.

2. We would expect that P(2 white cards) = P(1 white card)*P(2nd white card given 1 white card).This gives the equation 14/95 = 2/5 * x
Solving for x gives x = 7/19.

3. There are a total of 4 favorable results: 1, 4, 5, 6. Out of the 6 possibilities, this is a probability of 4/6 = 2/3.