1007. The method of the shoes

    Shall I write the name of the method I've chosen?

    Pepe Chapuzas asked this during a systems test. I suposed he meant elimination, substitution or equalization... but not... In his test there's no system...

    Problem:

    In a farm there were rabbits and chickens. There were 62 heads and 168 legs. ¿How many rabbits and haw many chicken were there?

    Pepe Chapuzas wrote this:

    Method of the shoes: The farmer bought a pair of shoes to each animal...
    There were  62  heads, that is,  62  animals.
    There were  62 · 2 = 124  shoes.
    There were  168 − 124 = 44  legs without shoes, that is, 44 rabbit hands.
    There were  44 : 2 = 22  rabbits.
    There were  62 − 22 = 40  chickens.