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Solution |
1) Robin owns 5 shirts, 3 pairs of pants and 2 pairs of shoes. Robin hates wearing the same outfit twice. Robin wears one shirt, one pair of pants and one pair of shoes each day.
How many more outfit options will Robin have if he adds one more pair of pants to his collection?
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- Robin's original number of combinations =
    5x3x2 = 30 combinations
- Adding one pair of pants:
    5x4x2 = 40 combinations
- He has 10 more options
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2) An octahedral die has the numbers 1 - 8 on its sides and has an equal chance of landing on any of its sides. What is the probability of rolling the same number three times in a row?
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- You get the first roll free!
(It establishes the number you must match)
- 1⁄8 x 1⁄8 = 1⁄64
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3)
It's jelly bean contest time. To change the contest a little, the librarian has students guess how many purple jelly beans are in the jar. Tilly applies a little statistics. She counts 36 jelly beans pressed up against one side of the jar and then counts 8 purple out of the 36. She also estimates that there are 520 total jelly beans in the jar. Based on these estimates and thinking that the jelly beans are pretty well mixed, what is a good estimate for the total number of purple jelly beans in the jar?
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- The proportion of purple jellybeans is 8/36 = 22.22%
- 0.2222 x 520 = 115.556 = 116 jellybeans
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