Notam x= pretul initial.
prima scumpire=12/100*x
pret dupa prima scumpire=x+12/100*x=112/100*x
a doua scumpire=15/100*112/100*x=1680/10000*x
pret dupa a doua scumpire=112/100*x+1680/10000*x=12880/10000*x
Notam p =procentul cerut.
x+p/100*x=12880/10000*x |:x
1+p/100=12880/10000
p/100=12880/10000-1
p/100=2880/10000
p=28.8
Procentul cerut este 28,8%.