Question 653302
you are ordering ice cream and have a choice of 3 toppings. you can have any or all the toppings. what are your possible choices?
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Rule: For each cone you either do or do not have each topping.
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Ans: 2^3 = 8 choices
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4 toppings how many choices. 
Ans: 2^4 = 16 choices
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n toppings?
Ans: 2^n choices
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Cheers,
Stan H.