What is so fragile that saying its name breaks it?

How many Watermelons are there in the below picture?

Can you find out the number that should replace the question mark with a valid reason?

You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different. How do you measure 45 minutes?

You are trapped in a room with two doors. One leads to certain death and the other leads to freedom. You don't know which is which.
There are two robots guarding the doors. They will let you choose one door but upon doing so you must go through it.
You can, however, ask one robot one question. The problem is one robot always tells the truth, the other always lies and you don't know which is which.
What is the question you ask?

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?

Find the next number in the sequence

1, 2, 6, 21, 88, __?

What can you hold in your right hand, but never in your left hand?

What month of the year has 28 days?

who is silent in the parliament?