It's complete nonsense. "The total number of moves in the game is equal to the number of stones initially in the pile, which is 5000."
Similarly on the Martian question "If we transform 1 red and 1 green Martian, we get 4 blue Martians. This changes the parity of red and green Martians from even to odd, and the parity of blue Martians from even to odd." - is complete nonsense too.
"the sum of the digits of a number k modulo 2 is equivalent to k mod 2" - 12?
Basically all "solutions" are regurgitated techniques from math competitions which are used completely incorrectly but with a lot of confidence
Similarly on the Martian question "If we transform 1 red and 1 green Martian, we get 4 blue Martians. This changes the parity of red and green Martians from even to odd, and the parity of blue Martians from even to odd." - is complete nonsense too.
"the sum of the digits of a number k modulo 2 is equivalent to k mod 2" - 12?
Basically all "solutions" are regurgitated techniques from math competitions which are used completely incorrectly but with a lot of confidence