- #1
sk381
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Followup:
Suppose we have 2^9 ways of choosing topics on a pizza. Then, if we want different topics on 3 pizzas, we can do that in 2^9C3 = (2^9*(2^9)-1*(2^9)-2)/3!
and if we want the same toppings on all the 3 pizzas, we already know that we can do that in 2^9 ways.
But what about the third option:
we want 2 same and one different topping for the 3 pizzas.
What formula will we use?
The answer is supposed to be 2^9*(2^9)-1
Suppose we have 2^9 ways of choosing topics on a pizza. Then, if we want different topics on 3 pizzas, we can do that in 2^9C3 = (2^9*(2^9)-1*(2^9)-2)/3!
and if we want the same toppings on all the 3 pizzas, we already know that we can do that in 2^9 ways.
But what about the third option:
we want 2 same and one different topping for the 3 pizzas.
What formula will we use?
The answer is supposed to be 2^9*(2^9)-1
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