Răspuns:
Explicație pas cu pas:
S = suma initiala
Prima data S/3
Rest S - S/3 = 2S/3
A doua data 1/5*2S/3 = 2S/15
Rest 2S/3 - 2S/15 = 10S/15 - 2S/15 = 8S/15
A treia data 1/2*8S/15 + 240 = 4S/15 + 240
Rest 8S/15 - (4S/15 + 240) = 8S/15 - 4S/15 - 240 = 4S/15 - 240
4S/15 - 240 = 240
4S/15 = 240 + 240 = 480
S = 15*480/4 = 1800 RON