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

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

If two fifty-foot ropes are suspended from a forty-foot ceiling that is twenty feet apart, how much rope will you be able to steal if you have a knife?

Who always enjoys poor health?

We have arranged an array of numbers below. What you have to do is use any kind of mathematical symbol you know excluding any symbol that contains a number like cube root. You can use any amount of symbols but you have to come up with a valid equation for all of them.

0 0 0 = 6
1 1 1 = 6
2 + 2 + 2 = 6
3 3 3 = 6
4 4 4 = 6
5 5 5 = 6
6 6 6 = 6
7 7 7 = 6
8 8 8 = 6
9 9 9 = 6

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

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?

In the picture given below, can you find out which digit will take place of the question mark?

Can you count the number of seconds in a year?

Clue: You need to bother about calculation.