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

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

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

Why do we preferably have round manhole covers and not square ones?

ENEMY = 2 * LINK
LINK + 2 = HELL

Then what will be TAXI + HELL? Select from the options below:
a) ROTTEN
b) DANGER
c) HEAVEN
4) MORTAL

He does not have any heart but still, He manages to live.
If you kill him, you will eventually die but yet you kill him.
He cannot run, who is He?

There are 4 big houses. They are made from the materials: red marble, green marble, white marble and blue marble.

* Mrs Jennifer's house is somewhere to the left of the green marble one and the third one alone is white marble.
* Mrs Sharon owns a red marbles house and Mr Cruz does not live at either end, but lives somewhere to the right of the blue marbles house.
* Mr Danny lives in the fourth house, while the first house is not made from red marble.

Who lives where, and what is their house made from?

How many times can you subtract the number 5 from 25?

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

Which city is three-fifths chick two third cat and 50% goat?