What Adam and Eve do not have but the rest of the people have?

A boy and his father are caught in a traffic accident, and the father dies. Immediately the boy is rushed to a hospital, suffering from injuries. But the attending surgeon at the hospital, upon seeing the boy, says 'I cannot operate. This boy is my son.' How is this situation explained?

Can you find out which triangle will have a bigger area among the following?
1. A triangle with sides 300, 400 and 500
2. A triangle with sides 300, 400 and 700

There is a place where if I stand up straight, I will still be considered sideways.

Can anyone tell me a word in the English dictionary which has a silent 'z'?

Find the number of squares in the below picture

10+10 and 11+11 can give you the same answer.

Explain how?

What does the below rebus riddle means?

Assume the given figure to be a delicious doughnut. Yes, now you can concentrate more on the puzzle. So you have this delicious doughnut in your refrigerator when your friends come knocking at the door. There are eight of them. Now you have to make three cuts in this doughnut so that each one of you nine people can enjoy a piece of it. Neither you nor your friends would mind the size of their piece as long as they are getting it. How will you do it?

I am never scared but became petrified and can’t live in a house but would die to make one. What am I?