In how many ways can a set of two positive integers less tha

In how many ways can a set of two positive integers less than 30 be chosen (First, determine whether or not the order matters)

Solution

There are 29 positive numbers from 1 to 30 (30 exclusive) and we need to select 2 numbers then we can select two numbers using:

²⁹C₂ = 406 ways

Order does not matter because we are selecting the numbers not arranging them.