what does this picture(rebus) riddle means ?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

In this image, you can see three almost identical Doraemon images. Can you spot the odd one out from them?

I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

Find out a multi-digit number that if multiplied by the number 9 or any of its multiplications products (i.e. 18, 27, 36, 45,..) will result in the multiplication factor repeated (n) number of times.

When monkey rotate the gear, which mark will be hit 1 or 2 ?

What is the next number in this matchsticks series riddle?

The below mentioned letters have been placed in a order using a logic.

DEAD, BALL, FEAR, SHOP

Can you find the logic?

Can you figure out the logic I used to decide the order of the following words:
gun, shoe, spree, door, hive, kicks, heaven, gate, line, den

Be active and find the killer in the picture Riddle below.