A man in a car saw a Golden Door, Silver Door and a Bronze Door. What door did he open first?

What number should come in place of the question mark below?

Here is a conversation between a couple who both are software professionals.

Husband: Hey! What is your date of birth?
Wife Replied Angrily: It is 591062400
Husband after doing some calculations replied, "Got It".

What is the DOB of the wife?

The peacock is a bird that does not lay eggs. How do they get baby peacocks?

What is always in front of you but can’t be seen?

By using all numbers, i.e. 123456789 and subtraction/addition, operators number 100 can be formed in many ways.
Example: 98 + 7 + 6 - 5 - 4 - 3 + 2 - 1 = 100

But if we add a condition use of the number 32 is a must. Then there are limited solutions.
One of such solution is: 9 - 8 + 76 + 54 - 32 + 1 = 100

Can you tell me any other solution?

Tell me the Hindi name of a Vegetable which if we remove 1st word will become a precious Stone and by removing the last word it will become a sweet eatable.

What is the word or phrase?

Which tank will fill first?

Buy me, smell me or deliver me, I do not change.

Who am I?