Răspuns:
Explicație pas cu pas:
S = suma avuta
Prima zi 2S/3 + 15
Rest S - 2S/3 - 15 = S/3 - 15
A doua zi 40/100 *(S/3 - 15) = 2/5 *(S/3 - 15) = 2S/15 - 6
Rest S/3 - 15 - 2S/15 + 6 = 5S/15 - 15 - (2S/15 - 6) = 3S/15 - 9 = S/5 - 9
S/5 - 9 = 27
S/5 = 27 + 9 = 36
S = 36*5 = 180 lei
A doua zi a cheltuit 2*180/15 - 6 = 24 - 6 = 18 lei