A survey of 508 adults aged 18-24 year olds was conducted in which they were asked what they did last Friday night. It found:
179 hung out with friends
193 ate pizza
38 watched TV and ate pizza, but did not hang out with friends
35 watched TV and hung out with friends, but did not eat pizza
26 hung out with friends and ate pizza, but did not watch TV
26 watched TV, hung out with friends, and ate pizza
54 did not do any of these three activities
How may 18-24 year olds (of these three activities) only watched TV last Friday night?