1)400000......100%
x.................30%
x=400000*30/100=120000
400000-120000=280000 lei
2)120000............100%
150000....................x
x=150000*100/120000=1500/12=125% este procentul
3)1280000.......100%
x..............10%
x=120000*10/100=12000
1280000+12000=1292000
1292000............100%
x.........................115%
x=1292000*115/100=1485800 lei dupa cele doua scumpiri