Below are some puzzles you need to solve to make a 4 letter word.
1.
105 35 315 ?
2.
I am the most important element in your surrounding. I was found by a Scottish physician. Who am I?
3.
I am made up of 3 digits. When you add the digits in me you will get a total of 11 and when you multiply the digits in me you get 9. My all digits are less then 10 and last digit is divisible by 3. What number am I?
When you have solved the above puzzles you will get some numbers and letters. Decode them, and you will get the required word.
Hint #1
You can decode them in any order. After decoding you need to rearrange them to get the required word.
Hint #2
Out of three puzzles, one puzzle will give you 2 identical letters.
Hint #3
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