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This key displays two menus: PRB and RAND.
PRB contains the following options:
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nPr |
Calculates the number of possible permutations of n items taken r at a time, given n and r. The order of objects is important, as in a race. n and r must be positive integers. |
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nCr |
Calculates the number of possible combinations of n items taken r at a time, given n and r. The order of objects is not important, as in a hand of cards. n and r must be positive integers. |
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! |
A factorial is the product of the positive integers from 1 to n. n must be a whole number { 69. |
RAND contains the following options:
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rand |
Generates a random real number between 0 and 1. To control a sequence of random numbers, store an integer (seed value) | 0 to rand. The seed value changes randomly every time a random number is generated. |
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randint( |
Generates a random integer between 2 integers, A and B, where A { randint { B. Separate the 2 integers with a comma. |
Examples
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nPr |
8 |
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< 3 < |
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nCr |
52 H 25 < |
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! |
4 H 3 < |
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STO 4 rand |
5 L H " |
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1 < |
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rand |
H " 1 < |
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randint( |
H " 2 3 % ` 5 E < |
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³ Problem
An ice cream store advertises that it makes 25 flavors of home made ice cream. You like to order three different flavors in a dish. How many combinations of ice cream can you test out over a very hot summer?
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25 |
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H 2 |
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3 < |
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You can choose from 2300 dishes with different combinations of flavors! If a long hot summer is about 90 days long, you will need to eat about 25 ice cream dishes each day!