To find the number of different special pizzas that can be made, we need to find the number of combinations of choosing 4 toppings out of 12 available toppings.
We can use the combination formula to solve this problem. The combination formula is given by:
C(n, r) = \frac{{n!}}{{r!(n-r)!}}
Where:
- n is the total number of items
- r is the number of items that we are choosing
In this case, we have 12 toppings to choose from and we want to choose 4 toppings. So we can plug in these values into the combination formula:
C(12, 4) = \frac{{12!}}{{4!(12-4)!}}
Now, let's simplify the expression:
C(12, 4) = \frac{{12!}}{{4!8!}}
Now, let's calculate the factorials:
C(12, 4) = \frac{{12 \times 11 \times 10 \times 9 \times 8!}}{{4! \times 8!}}
We can cancel out the 8! terms:
C(12, 4) = \frac{{12 \times 11 \times 10 \times 9}}{{4!}}
Simplifying further:
C(12, 4) = \frac{{12 \times 11 \times 10 \times 9}}{{4 \times 3 \times 2 \times 1}}
C(12, 4) = 12 \times 11 \times 10 \times 9 \times \frac{{1}}{{4 \times 3 \times 2 \times 1}}
C(12, 4) = 12 \times 11 \times 10 \times 9 \times \frac{{1}}{{24}}
Now let's calculate the product:
C(12,4)=12\times11\times10\times9\times\frac{{1}}{{24}}=495
Therefore, there are 495 different special pizzas that can be made from the 12 available toppings.
Answer: 495