For the first one the answer is that, no matter which numbers you choose,the answer will always be the last term plus the term before that. For example if you take the first three numbers in the Fibonacci sequence, 1,1,and 2 add them up you get four, then replace the first term in those three numbers with the next so, 1,2 and 3 you get six then if you replace the first term in those numbers, yet again, which is 1 you get the numbers 2,3,and 5. The sum of these is 10 which happens to be the sum of the 4 and 6 the two answers before that. I have tried this myself and, no matter which three numbers in the Fibonacci sequence, the conclusion doesn't differ.
For the second one the answer is even more apparent. OK take 4 consecutive numbers, then take the first and the last so, to start with, the first numbers 1 and 3, add these together which, in this case, is 4 and divide by two so, the answer is two now if we try this with the other numbers in the FIbonacci sequence output is 3 then 5 then 8 then 13. Now these are the numbers in the first terms of the Fibonacci sequence precisly the third of the numbers you picked. This will also work with the other consecutive numbers in the Fibonacci sequence.
THe same thing as in the last paragraph occures in this one too. what you should do is add six consecutive numbers in the Fibonacci sequence add them up and divide by four. For example take 1,1,2,3,5 and 8.1+1+2+3+5+8 is 20 divide that by four is five try it with the next numbers so 1+2+3+5+8+13 is 32 divide that by 4 you get 8 the next number in the sequence Fibonacci Sequence from 5.
I have also descovered that what i stated in the first paragraph doesent only work using three numbers, it also works with any number greater than 1.