Răspuns:
x/2+10=(x+20)/2 - prima zi
x-(x+20)/2=(x-20)/2 rest
(x-20)/2·1/3+16=(x-20)/6+16 - a2a zi
(x+20)/2+(x-20)/6+16+24=x
3x+60+x-20+96+144=6x
280=6x-3x-x
280=2x
x=280:2
x=140 lei suma initiala
(140-20):6+16=36 lei cheltuita a2a zi
(140+20):2=80 lei cheltuiti in prima zi
80-24=56 diferenta dintre prima zi si a3a zi