Without a doubt the most popular Pizza toppings in the United States are cheese and pepperoni. A close second is cheese, canadian bacon, and pineapple. In Europe, you will get totally different answers.
Here is a cool facts sheet for pizzas, including top toppings. Enjoy! http://www.pizzaware.com/facts.htm
4 pizzas
25
13
In Germany, the most popular toppings for pizza are typically cheese, mushrooms, ham, salami, and peppers.
Mistard
220
There are 7C5 = 7*6/(2*1) = 21 pizzas.
The most popular toppings to serve with roller dogs are mustard, ketchup, relish, onions, and sauerkraut.
A large Papa John's pizza will feed 3-4 adults. Their most popular combination of toppings is pepperoni, sausage and mushrooms.
If you must use all 5 with no repetition, you can make only one pizza. 5C5, the last entry on the 5 row of Pascal's triangle. If you can choose as many toppings as you want, all the way down to none (cheese pizza), then you have 5C0 + 5C1 + 5C2 + 5C3 + 5C4 + 5C5 = 32. Another way to think about it is no toppings would allow one pizza (cheese), one topping would allow two pizzas (cheese, pepperoni), two toppings would allow four pizzas, three toppings would allow eight pizzas, four toppings would allow sixteen, creating an exponential pattern. p = 2 ^ t. So, 10 toppings would permit 1024 different combinations
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To find the number of different 3-topping pizzas that can be made from 21 toppings, we first calculate the combinations of toppings. The number of ways to choose 3 toppings from 21 is given by the combination formula (C(n, k) = \frac{n!}{k!(n-k)!}). Thus, (C(21, 3) = \frac{21!}{3!(21-3)!} = 1330). Since there are 3 different crusts, the total number of 3-topping pizzas is (1330 \times 3 = 3990).