Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

In a jungle where there are no street lights or any other artificial source of lights, I notice a black snake crossing the road.
How did I get sight of the snake?

How will you measure 15 minutes using two hourglasses of 7 minutes and 11 minutes respectively?

After undergoing a successful eye operation, A blind girl has just boarded a train to her home. The doctor asked her to open the bandages after 3 hours. On her train journey, she opened the bandages and within a fraction of the time she commits suicide by jumping off the train.

Though her operation was successful, Why did she commit suicide?

What is the largest amount of money that you can possess in change and still if someone asks you for a dollar, you won't be able to give?

Trying to tease Birbal, Akbar gave him one gold coin and ask him to buy
* something for him to eat
* something for him to drink.
* something to feed the cows
* something to plant in the garden
and most important you need to buy only one thing.

What must Birbal buy to silence Akbar?

What is next number in the pattern below:

131 517 192 123 ?

There are three light switches outside a room. One of the switches is connected to a light bulb inside the room.
Each of the three switches can be either 'ON' or 'OFF'.

You are allowed to set each switch the way you want it and then enter the room(note: you can enter the room only once)

Your task is to then determine which switch controls the bulb?

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