What is so fragile that saying its name breaks it?

What can go through glass without breaking it?

Look at the picture and find out which square is not linked with any of the other squares.

If we tie a Sheep to one peg, a circled grass is been eaten by the Sheep. If we tie the Sheep to two pegs with a circle on its neck, then an eclipse is eaten out of the grass by the Sheep. If we want an eclipse then we put two pegs and then put a rope in between them and the other end of the rope is tied up on the Sheep's neck.

How should we tie the peg and the Sheep so that a square is eaten out from the garden grass? We only have one Sheep rope and the peg and the rings.

Below the four parts have been reorganised. The four partitions are exactly the same in both arrangements. Why is there a hole?

Transform the word THINK into BRAIN while changing only one letter at a time in a manner that each of the word in the process is a real word!!!

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?

I have branches, but no fruit, trunk or leaves. What am I?

I am a type of vehicle that has two wheels and is powered by humans. What am I?
Hint 1: You can ride me for exercise.
Hint 2: I am environment-friendly.

What is black when you buy it, red when you use it, and gray when you throw it away?