suma = x1. prima cheltuiala 1/4 din suma = x/4
primul rest = x - x/4 = 3x/42.
a doua cheltuiala de 1/6 din rest = 3x/4 * 1/6 = 3x/24 = x/8
au mai ramas x- ( x/4+ x/8) = (8x - 2x - x )/8 = 5x/ 8 3.
a treia cheltuiala = 1/3 * 5x/8 = 5x/24 x/4 + x/8 + 5x/24 +120 +600 = x = 14x/24 + 720 = x ==> x-14x/24 = 720 ==>x = 720*24: 10 = 1728