Apizza parlor offers 5 different pizza toppings. how many different kinds of 2-topping pizzas are available?

So let's pretend there is olives, pepperoni, jalapenos, sausage, and pineapple. Here is an example of an outcome chart that is useful when it comes to these type of problems.

                 sausage
                     l
pineapple-olives-pepperoni
                     l
              jalapenos
           

1. Olives and sausages
2. olives and pepperoni
3. olives and jalapenos
4. olives and pineapple
5. sausages and pepperoni
6. sausages and jalapenos
7. sausage and pineapple
8. pepperoni and jalapenos
9. pepperoni and pineapple
10. pineapple and jalapenos

There are 10 total 2 topping pizzas possible.

Now I'm hungry...

Hope this helps!

Sin(a)+cos(a)+cot(a)-1=2(csc(x)+1)