How can you write nineteen in a manner that if we take out one, it becomes twenty?

What mathematical symbol can be put between 5 and 9, to get a number bigger than 5 and smaller than 9?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

Can it be possible to build a house that has all its four walls facing towards the South?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

My first is in chocolate but not in ham. My second is in cake and also in jam. My third at tea time is easily found. Altogether, this is a friend who is often around. What is it?

What Does this text mean:

important=important

A woman is sitting in her hotel room and hears a knock at the door. She opens the door to see a man whom she’s never met before. He says, “I’m sorry, I have made a mistake, I thought this was my room.” He then goes down the corridor and into the elevator. The woman goes back into her room and calls security. What made the woman so suspicious of the man?

He runs but never walks. Murmurs, but never talks. Has a bed, but never sleeps. And has a mouth, but never eats?

In a box, there is a jumble of 7 red balls, 6 blue balls, 5 green balls, and 4 yellow balls. What is the minimum number of balls, will you have to pick up so that you have at least 4 balls of the same colour?