4 Millimeters decrease to 3 millimeters what's the percent of decrease

Zoey made 5 1/2 cups of trail mix for a camping trip. she wants to divide the trail mix into 3/4 cup servings. a. ten people are going on the trip. can zoey make enough 3/4 cup servings so that each person gets one serving? b. what size would the servings need to be for everyone to have a serving?

How do i simply this radical expression?

Suppose you have 10 skittles. 5 green and 5 red. you choose 4 without looking. what is the probability that all 4 skittles will be green?