how do i start to solve this

Harry has a choice of a veggie burge and a regular pizza
he can have three toppings his choices are
lettuce pickles onions tomatos and sprouts that is five items
how many combinations can he have
I think i multiply 5 x 3 and get 15 can you tell me is this right

First topping:

5 choices
sEcond choices 4 toppings
third choice 3 toppings

Answer: 5*4*3

nCr= N!/(n-r)!

To solve this problem, you need to use the concept of combinations, specifically the formula for finding combinations when order doesn't matter. The formula is as follows:

nCr = n! / (r!(n-r)!)

In this case, there are 5 toppings available (lettuce, pickles, onions, tomatoes, and sprouts) and Harry can choose 3 toppings. So, you want to calculate 5C3.

Now, let's break down the calculation step by step to find the number of combinations:

1. Calculate the factorial of the total number of choices (n):
n! = 5! = 5 x 4 x 3 x 2 x 1 = 120

2. Calculate the factorial of the chosen number of toppings (r):
r! = 3! = 3 x 2 x 1 = 6

3. Calculate the factorial of the remaining toppings (n-r):
(n-r)! = (5-3)! = 2!

4. Simplify the expression:
5C3 = 5! / (3!(5-3)!) = 5! / (3!2!) = 120 / (6 x 2) = 120 / 12 = 10

So, the correct answer is 10 combinations that Harry can have.

To summarize, you should use the combination formula nCr = n! / (r!(n-r)!) to solve this problem. Calculate the factorials of the individual components and simplify the expression to find the correct answer.