What's the only room from which no one can enter or leave

What month of the year has 28 days?

Jim has three close friends at his school: Michael, John and Alice. Two of them play football, two play basketball and two play hockey. The friend who does not play hockey does not play basketball as well. The friend who does not play football does not play hockey.

Can you identify which sport/s is played by which person?

It belongs to you, but other people use it more than you do. What is it?

Consider this about a word: The first two letters signify a male, the first three letters signify a female, the first four letters signify a great, while the entire world signifies a great woman. What is the word?

There is a barrel with no lid and some wine in it. 'This barrel of wine is more than half full,' said Curly. 'No it's not,' says Mo. 'It's less than half full.' Without any measuring implements and without removing any wine from the barrel, how can they easily determine who is correct?

I taste better than I can smell. Who am I?

Which number should replace the question mark?

If 2 workers can complete painting 2 walls in exactly 2 hours.

How many workers would be needed to paint 18 walls in 6 hours?

A man is shown a portrait painting. He looks closely, then tells, “Brothers and sisters have I none, but that man’s father is my father’s son!” Who is the man in the portrait?