Can you find out the next digit in the following series ?

0, 0, 1, 3, 2, 6, 3, 9, 4, 12, 5, ?

I get hot but I never sweat,
I cook food but I am not a chef,
I have a door but you can't enter me,
I have a light but I am not a lamp.
Who am I?

A famous swimmer can swim downstream in a lake in exactly 40 minutes with the lake current.
He can swim upstream in that lake in exactly 60 minutes against the lake current.
The length of the lake is 2 km.

How long he can cover the distance of one side at a still lake with no current?

You have a roll of cloth 1km long. You have a machine which cuts this roll into pieces of 10-meter-long cloth.

How long would it take for the machine to cut the roll if each cut took 4 secs?

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

How can one talk without saying a single word?

What country can make you shiver?

How many words can a pen with half refill write?

Can you decipher the following common phrase?

T M C
A U O
H S M
W T E

I have lakes with no water, mountains with no stone and cities with no buildings. What am I?