Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

Thirty friends were on a hiking trip when they decided to enjoy the bonfire. They assembled for it and agreed to play a game. For that, they divided themselves into five teams with seven members each, forming five rows.

How did they manage to achieve this formation?

It is always ahead of me yet I can never see it. What is it?

What number divided by 4 is the same as that number minus 4?

You can see it everyday, But cannot touch it at will. What is it?

You have two buckets of 11 liters and 6 litres.
How can you measure exactly 8 litres?

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?

I have 50 feet long of cloth, I need to create 50 handkerchiefs each size of 1 foot. I take one minute to cut a 1-foot handkerchief. So how long will it take to cut 50 handkerchiefs?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?