Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

John and Jenni are a married couple. They have two kids, one of them is a girl. Assume safely that the probability of each gender is 1/2.
What is the probability that the other kid is also a girl?

Hint: It is not 1/2 as you would first think.

A Shopkeeper collects 71 rupees in the form of 20 paisa and 25 paisa.
He collects a total of 324 coins.

Can you tell me how many number of 20-paisa and 25-paisa he got?

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?

Prove that twice of ten is the same as twice of eleven.

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

How many triangles can you find in this given picture?

A newspaper is supposed to have 60 pages, but pages 24 and 41 are missing.
Which other pages won't be there?

Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?