2, 3, 5, 9, 17, _ What is the next number in the sequence?

What is full of holes but still holds water?

I am not alive, but I grow; I don't have lungs, but I need air; I don't have a mouth, but water kills me. What am I?

Here is a Swiss Cross. You have to make two straight cuts in the figure so that it is divided into four congruent pieces. Also, you should be able to join these pieces into a square then. Can you accept this challenge?

What is the centre of gravity?

ENEMY = 2 * LINK
LINK + 2 = HELL

Then what will be TAXI + HELL? Select from the options below:
a) ROTTEN
b) DANGER
c) HEAVEN
4) MORTAL

Using Only Five 5's and any mathematical operator make sum as 37

Twice ten are six of us,

Six are but three of us,

Nine are but four of us;

What can we possibly be?

Would you know more of us?

Twelve are but six of us,

Five are but four, do you see?

What are we?

What does a man do only once in his lifetime, but women do once a year after they are 29?

I am lying and I always lie. Tell me whether I am lying or telling the truth.