The 1st diagram is incomplete, because it doesn't show the possibility that with jeans, also Hiking boots could be selected & with the Khakis, sneakers
The 2nd is right since it's showing all possibility, but the last diagram is "J" is incomplete
Problem 2:
Sample Space={H-R,H-B,H-G,H-Y, T-R,T-B,T-G,T-Y}
Problem 3:
The total number of choices to get one sandwich is:
Sandwich 2 Choices, 3 Sides & 3 beverages = 2x3x3= 18