Would greatly appreciate for whoever helps

Pizzas

There are 14 possible toppings.

There are 14 ways to chose one topping

There are 14C2 ways to choose 2 toppings

...

There are 14C14 = 1  way to chose all 14 toppings.

 

Add them all together to get the number of possibilities.

If you think it is relevant you can add 1 which is the number of ways you can make a pizza with no toppings. 

 

Prob of guessing correctly is 1/total.

But not all topping choices would be equally likely so it is not really that simple.