81 x 9 = 801. What must you do to make the this equation true?

What does this below rebus puzzle mean?

Replace the question mark with the correct number.

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

If I put in one canary per cage, I have one bird too many. If I put in two canaries per cage, I have one cage too many. How many cages and canaries do I have?

Can you spot the man between the coffee bean in the picture below ?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

I am a ten letters word
The first four letters have the power to rule,
Next, four-letter can be eaten.
The next three-letter represents a lady.
I can fly as well

what am I looking for?

You are an expert on paranormal activity and have been hired to locate a spirit haunting an old resort hotel. Strong signs indicate that the spirit lies behind one of four doors. The inscriptions on each door read as follows:

Door A: It's behind B or C
Door B: Its behind A or D
Door C: It's in here
Door D: It's not in here

Your psychic powers have told you three of the inscriptions are false, and one is true. Behind which door will you find the spirit?

Which alphabet is a part of our body?