Fun Riddles

Question: No matter how hard you try,
I can open what you can't.
If it wasn't for me,
on your front porch you would stand.

What am I?

Question: I am a cave full of bones,
and the house of a worm.

What am I?

Question: A man challenges the greatest chess player in the world to two games of chess. He guarantees that he will win or tie at least one of the games for sure. To be even more cocky, the man says he will play both games at the same time.

How does he guarantee he wins or ties at least one game?

Question: I turn polar bears white
and I will make you cry.
I make guys have to pee
and girls comb their hair.
I make celebrities look stupid
and normal people look like celebrities.
I turn pancakes brown
and make your champagne bubble.
If you squeeze me, I'll pop.
If you look at me, you'll pop.

Can you answer the riddle?

Question: A man has 3 children and half of them are girls, how is this possible?