This is an ancient Math Puzzle before Algebra was invented, so the ancient intelligent Chinese used this funny “Method of Elimination” below:
Puzzle: In a cage housing some chicken and rabbits. There are total of 35 heads, and 94 legs. Find how many chicken and rabbits ?
Imagine letting each animal raises up 2 legs, then there would be 35x2 = 70 legs raised.
94 – 70 = 24 legs
Note that all chicken raising 2 legs would have fallen on ground (no leg how to stand ?), so the 24 remaining legs still standing on the ground MUST belong ONLY to the rabbits standing on 2 legs (the other 2 legs raised up)
24 / 2 = 12 rabbits (Ans)
35 – 12 = 23 chicken (Ans)