Răspuns:
Explicație pas cu pas:
S = suma initiala
prima zi 60%S = 60S/100 = 6S/10
rest S - 6S/10 = 10S/10 - 6S/10 = 4S/10
a doua zi 40/100*4S/10 = 16S/100
rest 4S/10 - 16S/100 = 40S/100 - 16S/100 = 24S/100
a treia zi 24S/100
6S/10 - 24S/100 = 108
60S/100 - 24S/100 = 108
36S/100 = 108
S = 108*100/36 = 300 lei