Questions
100

"Three people I know don’t like pineapple on pizza. Nobody likes it!"

Yes, sample size is too small. 

200

“I knew a guy who went to jail for assault. He used to play video games all the time. This just proves my point that video games cause people to become violent. ”

Yes, broad conclusion off a small sample size. 

300

"Out of 1,000 surveyed drivers, 78% say they prefer electric cars. So, electric cars are becoming more popular."

No, there is sufficient mathematical evidence. 

400

“Numerous studies in psychology have shown that students who average at least 8 hours of sleep before a test generally perform better than those who did not sleep well”

No, sufficient evidence based on multiple studies & large sample size.