1. Mutually exclusive:-
Two events are 'mutually exclusive' if they cannot occur at the same time. An example is tossing a coin once, which can result in either heads or tails, but not both.
In the coin-tossing example, both outcomes are collectively exhaustive, which means that at least one of the outcomes must happen, so these two possibilities together exhaust all the possibilities. However, not all mutually exclusive events are collectively exhaustive.
For example, the outcomes 1 and 4 of a single roll of a six sided die are mutually exclusive (cannot both happen) but not collectively exhaustive (there are other possible outcomes; 2,3,5,6).
For example,
Let A be the event of rolling 4 on a die. What is the probability of not rolling 4?
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The probability that we don't roll 4 is equal to
2. Independent event:-
Two events are if the occurrence of one has no
effect on the occurrence of the other. For instance, if a coin
is tossed twice, the outcome of the first toss (heads or tails) has no effect on the
outcome of the second toss.
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For example,
| A dresser drawer contains one pair of socks with each of the following colors: blue, brown, red, white and black. Each pair is folded together in a matching set. You reach into the sock drawer and choose a pair of socks without looking. You replace this pair and then choose another pair of socks. What is the probability that you will choose the red pair of socks both times? |
| There are a couple of things to note about this experiment. Choosing a pairs of socks from the drawer, replacing it, and then choosing a pair again from the same drawer is a compound event. Since the first pair was replaced, choosing a red pair on the first try has no effect on the probability of choosing a red pair on the second try. Therefore, these events are independent. Solution:-P(red) = 1/5 P(red and red) = P(red) · P(red) = 1/ · 1/55 = 1/25. For example, |
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