What does the below rebus riddle means?

I am a word that begins with the letter “i.” If you add the letter “a” to me, I become a new word with a different meaning, but that sounds exactly the same. What word am I?

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

Can you place three balls such that the equation shown in the picture holds true?

Do you know who was buried in John's tomb?

I am thinking of a five-digit number such that:
The first and last digits are the same, their submission is an even number and multiplication is an odd number and is equal to the fourth number. Subtract five from it and we obtain the second number. Then divide into exact halves and we get the 3rd number.

What number I am thinking of?

What do you get if you add 2 to 100 four times?

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

My cousin lives in one story house in Antarctica. His house is made the of-of sandstone. what is the color of stairs?