If the teacher chooses 2 students, what is the probability that both of them forgot their lunch?

Question

In a class of 10, there are 2 students who forgot their lunch.

Answer 1

The teacher's first choice has a 2/10 chance of being successful. Now there are only 9 students and only 1 who forgot their lunch, so the chance of picking that person is 1/9. The chance of both choices being successful (the problem states the teacher must get both right) is 2/10 times 1/9, which equals 1/45.