The box on page 305 gives you the BASIC PROBABILITY PRINCIPLE.You may be asked to find multiple probabilities given the same sample set.Notice then, that the sample space (your denominator) will not change with every part of the problem, and therefore should be the first thing you find. If you look at parts a and b in EXAMPLE 6, you will see exactly this.

1.Read part c in EXAMPLE 6 on page 305.What can you conclude about P(something impossible)?

2.Give another example of rolling a single die that would result in an impossible probability.

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