The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

Find the next number in the series below

21 32 54 87 131 ?

Eight Chelsea player makes the following statements :

1. Seven of us are lying here.
2. Six of us are lying here.
3. Five of us are lying here.
4. Five of us are lying here.
5. Four of us are lying here.
6. Three of us are lying here.
7. My name is Torres.
8. My name is Lampard.

The last two are Lampard and Torres or maybe Torres and Lampard.
So can you deduce which of the last two is Lampard or Torres?

In a Society, there are over 100 flats.

Flat 1 is named the first flat.
Flat 2 is named the second flat.
Flat 3 is named the third flat. And So On.....

A visitor decides to walk through all the flats, and he finds all the flats except flat 62.
Anmol later founds that the locals of the town have given it another name.

What is the name of the Flat?

What has many keys but can’t open a single lock?

All of Jacob's shoes are red except two.
All of Jacob's shoes are green except two.
All of Jacob's shoes are yellow except two.

How many shoes does Jacob have?

Count the number of triangles in the given picture.

I make two people out of one. 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.

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?