What is so fragile that saying its name breaks it?

Akbar called Birbal and asked him to draw a line on the floor. He asked Birbal to make that line smaller without erasing it. Birbal smiled and did it before Akbar could blink his eyes.

How did he managed to do it?

I’m tall when I’m young, and I’m short when I’m old. What am I?

I add 5 to 9 and get 2. The answer is correct, so what am I?

I am Huge on Sunday and Saturday.
I am small from Tuesday to Thursday.
I do not exist on Monday and Friday.
Who am I?

There is something which you can be arrested for attempting but not for successfully completing.

The two towns are exactly 100 km apart. John leaves City A driving at 30 km/hr and Jacob leaves City B half an hour later driving at 60 km/hr. Who will be closer to City A when they meet?

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

What breaks yet never falls, and what falls yet never breaks?

Solve the below puzzle by replacing the question mark with the correct number.

3 6 12

4 8 16

5 10 ?