Answer:
9/70
Explanation:
Given that:
70 students choose to attend one of three after school activities: football, tennis or running.
There are 30 boys. 13 students choose football, of which 9 are girls. 31 students choose tennis. 9 girls choose running.
A student is selected at random.
What is the probability this student chose running?
Since it asking for the probability of this student (randomly select) chose running. And we can see that there are 9 girls choose running.
Therefore, we also know 70 students is the total
Hence, the answer is 9/70
9/70 is in simplest form already.
~lenvy~