What is the Surname of Barbie Doll?

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?

Shyla was sleeping in her apartment when suddenly a robber broke into her house. He asked her to stay quiet and started looting the cash and jewelry. Suddenly the landline phone started ringing. The robber pointed a gun at Shyla and asked her to pick up and talk without giving away the situation.

She picked up the phone and it happened to be her husband. She spoke, Is it an emergency darling? Do give me a call when your flight lands, I will prepare your favorite food that will help you relieve the stress. Then she hanged up.

10 minutes after, the police arrive at the scene and catch the robber. How did the police know about the robbery?

Can you count the number of triangles in the picture below?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

All of the flowers I have are orchids except two. All of the flowers I have are hibiscuses except two. All of the flowers I have are roses except two.

Can you tell me how many flowers I have?

Can you make a six-letter word using the letters N, A and B ?

Solve the equation by replacing the alphabet with numbers.

MOM + MOM + NO = BOOK=

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?