When a customer buys a familysized meal at certain restaurant, they get to choose 3 side dishes from 9 options. Suppose a customer is going to choose 3 different side dishes.How many groups of 3 different side dishes are possible?
Q. When a customer buys a familysized meal at certain restaurant, they get to choose 3 side dishes from 9 options. Suppose a customer is going to choose 3 different side dishes.How many groups of 3 different side dishes are possible?
Identify problem type: Identify the problem type.We need to find the number of combinations of 3 side dishes that can be chosen from 9 options. This is a combination problem because the order in which the side dishes are chosen does not matter.
Use combination formula: Use the combination formula.The number of ways to choose 3 items from 9 is given by the combination formula: C(n,k)=k!(n−k)!n!, where n is the total number of items to choose from, k is the number of items to choose, "!" denotes factorial, and C(n,k) is the number of combinations.
Calculate number of combinations: Calculate the number of combinations.Using the combination formula with n=9 and k=3, we get:C(9,3)=3!(9−3)!9!=3!6!9!=3×2×19×8×7=6504=84.