Answer:
20
Step-by-step explanation:
First, rewrite the numbers in numerical order:
8, 10, 10, 15, 15, 20, 20, 20, 20, 25, 25, 25, 35
Then find the middle number: (note there's 6 numbers on each side of 20)
8 10 10 15 15 20 20 20 20 25 25 25 35
Hope this helps!