Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

If,

A = 1

B = 2

C = 3

...

...

Z = 26.

Based on above rule, you need to find an eleven letter word whose letter sum is equal to 52.

A boy and his father are caught in a traffic accident, and the father dies. Immediately the boy is rushed to a hospital, suffering from injuries. But the attending surgeon at the hospital, upon seeing the boy, says 'I cannot operate. This boy is my son.' How is this situation explained?

Solve the following series:
AZ, GT, MN, __, YB

When it's bad luck to meet a black cat?

What does this mathematical rebus means ?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

When it is alive we sing, when it is dead we clap our hands. What is it?

Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?

There is one thing that goes round the house and also inside the house but never even share a brief touch. What is it?