What does the below image rebus riddle means ?

What is black when you buy it, red when you use it, and gray when you throw it away?

Find The Missing Number, 99% of People Fail To Solve This Table, Can You?

Using mathematical symbols like +, -, and x in order to make the equations correct. Replace # with the above-given symbols.

9 # 8 # 7 # 6 # 5 # 4 = 91

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

Can you make a six-letter word using the letters N, A and B ?

There are two beautiful yet remote islands in the South Pacific. The Islanders born on one island always tell the truth, and the Islanders from the other island always lie.
You are on one of the islands and meet three Islanders. You ask the first which island they are from in the most appropriate Polynesian tongue, and he indicates that the other two Islanders are from the same island. You ask the second Islander the same question, and he also indicates that the other two Islanders are from the same island.
Can you guess what the third Islander will answer to the same question?

Solve the mathematical equation in the picture below.

Identify Me

Hint1: I am a god
Hint 2: I am a planet
Hint 3: measurer of heat

Intelligence Agency need to break the vault but the problem is that they are not able to break the vault.

On the vault, a text is written as:

31 11 33 33 43 45
21 25
31 24 11 31 51 41

To Break the code Intelligence Agency brings a mathematician named Joseph.
Minutes later he deciphers the code.

Whats the code?