What does below rebus means ?

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

Imagine a box with two cogwheels, one big with 24 teeth and one small with 8 teeth. The big one is firmly attached to the center of the box which means it does not turn or move while the small one rotates around the big one.

How many times do you think that the smaller wheel will turn compared to the box when it turns once around the big one?

Rearrange the letters in "new door" to make one word.

If you toss a coin 10 times and it lands heads up every time, what are the chances it will land heads up if you toss it again?

The captain of a ship was telling this interesting story: "We travelled the sea far and wide. At one time, two of my sailors were standing on opposite sides of the ship. One was looking west and the other one east. And at the same time, they could see each other clearly." How can that be possible?

If eleven plus two equals one, what does nine plus five equal?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?

Which is the correct shadow of the bird?