The ice-cream parlor sells sundaes with 3 different types of ice-cream and 4 different toppings. They have 8 flavors of ice-cream and 10 toppings for their customers to choose from.
The total number of different types of sundaes that can be bought by a person is equal to C(8,3)*C(10,4) = 11760
The number of options that have the topping cookie crumbles is C(8,3)*C(9,3) = 4704
This gives the probability that a customer buys a sundae with the topping of cookie crumbles as `4704/11760 = 2/5` .
There is 40% probability that a sundae with a topping of cookie crumbles is bought by a customer.