Which tank will fill first?

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

Can you find the company name in the pictogram below?

What has lots of eyes, but can’t see?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

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

PS: You may start the number from 0.

If you drop me I’m sure to crack, but give me a smile and I’ll always smile back. What am I?

A woman shoots her husband.

Then she holds him under water for over 5 minutes.

Finally, she hangs him.

But 5 minutes later they both go out together and enjoy a wonderful dinner together.

How can this be?

What am I?