108 students choose to attend one of three after school activities: football, tennis or running. There are 40 boys. 37 students choose football, of which 26 are girls. 39 students choose tennis. 12 girls choose running. A student is selected at random. What is the probability this student chose running? Give your answer in its simplest form.

8/27

Step-by-step explanation:

First, we figure out how many students chose each school activity, so that we can find the probability of a student at random choosing running by putting (total running students)/(all students).

39 students chose tennis, as stated in the problem.

37 students chose football, as stated in the problem.

The total number of students who chose running must therefore be the the students who chose tennis and football, subtracted from the total number of students. 108 - 39 - 37 = 32, so 32 students chose running.

Therefore, the probability that a student at random chose running would be 32/108 or 8/27.