pret initial 9 lei
1.ieftinire 10%
100%-10%=90%
9×90%=8,1 lei raspuns corect c)
2.scumpire 10%
100%+10%=110%
9×110%=9,9 lei raspuns corect a)
3. 2 scumpiri succesive 10%
100%+10%=110%
9×110%=9,9 lei
100%+10%=110%
9,9×110%=10,89 lei raspuns corect d)
4. o ieftinire 10% + o scumpire 10%
100%-10%=90%
9×90%=8,1 lei
100%+10%=110%
8,1×110%=8,91 lei raspuns corect b)
