1) 18/54=1/3
13/0,1(4)=13/13/9=1/9
2) 10% din 250= 10/100*250/1=25 lei
250-25=225
3) z1= prima zi
z2= a doua zi
z3= a treia zi
z1=1600/1*25/100=16*25=400
z2=(1600-400)*10/100=1200/1*10/100=120
z3=1200-120=1080
4)6/8=18/24=2/3
nu cred ca este posibil
5)x=25*4/10=100/10=10
x=40/5=8
