A-pretul initial
scumpirea: A+10/100xA=A+A/10=(10A+A)/10=11A/10
ieftinirea: 11A/10-(10/100)x11A/10=11A/10-11A/100=(11Ax10-11A)/100=
=(110A-11A)/100=99A/100
99A/100=118.800
A=(118.800x100)/99
A=120.000 lei pretul initial
b) 120.000xp/100=118.800
p=(118.800x100)/120.000
p=99%
120000x99/100=118.800