a pizza store offers 15 different toppings on its pizzas.

what is the probability that 4 randomly selected toppings will include salami and green pepper?

There are 15 choose 4 ways to choose 4 toppings. There are 15 choose 2 ways to choose salami, green pepper, and 2 other toppings.

P{salami and green pepper) = C(15, 2) / C(15,4).

A pizza parlor has a choice of toppings for its pizzas. From these toppings, how many different -topping pizzas can be ordered? Assume that the order in which the toppings are listed does not matter.

To find the probability of selecting salami and green pepper as 2 out of 4 randomly selected toppings, we need to consider the following:

1. Total Number of Toppings:
Since the pizza store offers 15 different toppings, the total number of toppings available is 15.

2. Number of Possible Combinations:
To find the number of possible combinations of selecting 4 toppings out of 15, we can use the combination formula (nCr):
nCr = n! / (r!(n-r)!)
where n is the total number of items and r is the number of items to be selected.

In this case, n = 15 and r = 4:
15C4 = 15! / (4!(15-4)!)

3. Number of Combinations with Salami and Green Pepper:
Since we want to find the number of combinations with salami and green pepper included, we need to consider that out of the 4 toppings, 2 are already fixed (salami and green pepper). So, we need to find the number of combinations of selecting the remaining 2 toppings out of the remaining 13 toppings after removing salami and green pepper from the list.

This can be calculated using the combination formula again:
13C2 = 13! / (2!(13-2)!)

4. Probability:
To find the probability, we divide the number of combinations with salami and green pepper (from step 3) by the total number of combinations (from step 2):
Probability = (Number of Combinations with Salami and Green Pepper) / (Number of Total Combinations)
Probability = (13! / (2!(13-2)!)) / (15! / (4!(15-4)!))

Now we can simplify the expression and calculate the probability.

To find the probability that 4 randomly selected toppings will include salami and green pepper, we need to consider the total number of possible combinations of toppings and the specific combination we're interested in.

First, let's determine the total number of possible combinations. Since there are 15 different toppings available, we have 15 choices for the first topping, 14 choices for the second topping, 13 choices for the third topping, and 12 choices for the fourth topping. So, the total number of possible combinations is calculated as:

15 * 14 * 13 * 12 = 32,760

Next, let's determine the number of combinations that include salami and green pepper. Since we're interested in a specific combination, we can treat salami and green pepper as fixed choices. Therefore, we have 1 choice for salami and 1 choice for green pepper. For the remaining 2 toppings, we have 13 choices for the first topping and 12 choices for the second topping. So, the total number of combinations that include salami and green pepper is:

1 * 1 * 13 * 12 = 156

Finally, we can calculate the probability by dividing the number of combinations that include salami and green pepper by the total number of possible combinations:

Probability = Combinations with salami and green pepper / Total combinations
= 156 / 32,760
= 0.00476

Therefore, the probability that 4 randomly selected toppings will include salami and green pepper is approximately 0.00476 or 0.476%.