What do you call a fish without an eye?

If an electric train is travelling south, then which way is the smoke going?

I have a hole in my back and legs I lack.
I live where I can’t breathe and I eat without teeth.
What am I?

'S' refers to the number of seconds in a day and 'H' refers to the number of hours in ten years. Which quantity out of these two is greater?

What is the probability of choosing the correct answer at random from the options below?

a) 1/4
b) 1/2
c) 1
d) 1/4

I am quite hot but become too cold if you remove the first two letters. What am I?

A mile-long train is moving at sixty miles an hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?

The following alphametic has only one solution. Can you find it?
ENLIST + SILENT + LISTEN = ANAGRAM

PS: You may start the number from 0.

Where do fish keep their money?

I am white when I am dirty, and black when I am clean. What am I?