A survey of 506 adults aged 18-24 year olds was conducted in which they were asked what they did last Friday night. It found: • 185 watched TV • 172 hung out with friends • 185 ate pizza • 39 watched TV and ate pizza, but did not hang out with friends • 34 watched TV and hung out with friends, but did not eat pizza • 32 hung out with friends and ate pizza, but did not watch TV • 29 watched TV, hung out with friends, and ate pizza How may 18-24 year olds did not do any of these three activities last Friday night?