A group of 100 outdoor enthusiasts were asked which activities they participated in: Hiking, Cycling, and Swimming.
10 people participated in all three activities.
22 people participated in Hiking and Cycling.
18 people participated in Cycling and Swimming.
25 people participated in Hiking and Swimming.
55 people participated in Hiking.
45 people participated in Cycling.
40 people participated in Swimming.
How many of the enthusiasts participated in none of the three activities?