To solve this problem, let’s first subtract the ones that ARE wearing green from the total number of volunteers. We’ll subtract 7 from 25 for an answer of 18. Then, we’ll put the 18 over 25 and this will represent how many volunteers are NOT wearing green out of the total number of volunteers. My work is below, please let me know if you have any questions! :)
25 - 7 = 18
18/25 = Probability of volunteers NOT wearing green out of the total number of volunteers