A student must select 2 subjects from the following 5 options: Commerce, Economics, Statistics, Mathematics 1, and Mathematics 2. Note that Mathematics 2 can only be chosen if Mathematics 1 is also selected. How many different pairs of subjects can the student choose?

Explanation

First, consider the number of pairs that do not include Mathematics 2. There are 4 subjects excluding Mathematics 2, so the number of ways to select 2 from these 4 is 4C2 = 6. Next, if Mathematics 2 is chosen, Mathematics 1 must also be selected, resulting in exactly 1 valid pair: (Mathematics 1, Mathematics 2). Adding these together, the total number of valid combinations is 6 + 1 = 7.