What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

I’m orange, I wear a green hat and I sound like a parrot. What am I?

What month of the year has 28 days?

I was speeding and ran through a stop sign, yet two traffic officers who were there do nothing about it.

why?

Living above a star, I do not burn
Eleven friends and they do not turn
I can just be visited in a sequence, not once or repeatedly
PQRS are my initials
Can you tell my name accurately?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

You can win me and lose me but never buy me
You can not eat me and never want to part with me
I can make you cry or bring you joy
I am not a machine and definitely not a toy
You keep me but i am not forever just yours
You might find me in a case or on a shelf next to a vase
I am hard and i am tall if you bump me i am sure to fall
I am made of different materials and am at many events
If your lucky and fight hard I might be yours
What am I ?

In the addition below, all digits have been replaced by letters. Equal letters represent equal digits and different letters represent different digits.
ABCABA
BBDCAA
ABEABB
ABDBAA
------- +
AAFGBDH
What does the complete addition look like in digits?

If,
29 - 1 = 30
9 - 1 = 10
14 - 1 = 15

Based on similar logic, Can you prove that the below algebraic equation is true?
11 - 1 = 10 ?

Look at this sequence from top to bottom. What is the next number in the sequence?
1
11
21
1211
111221
312211