Two people are independently choosing a 3-topping pizza with 4 possible types of crust and 7 possible toppings. What is the probability that they choose the same exact crust and toppings combination?

Question

anonymous · Answer

it depends can they choose to put the same topping on more than once

anonymous · Answer

They only can use it once

anonymous · Answer

okay than they first would choose 1 topping out of 7 than another out of 6 than another out of 5, so they would have 1 out of 7 x 6 x 5 chance of getting the same topping combo then they choose 1 out of 4 crust types so you multiply the other equation by 1/4 

so they would have a probability of one out of 210x4 or 1/840

anonymous · Answer

Thank you