fie P pretul initial
dupa prima scumpire devine P +10P/100=110P/100=1,1P
dupa a doua scumpire eldevine
1,1P + (10/100)*1,1P=1,1P +0,1*1.1P=1,1P(1+0,1)= 1,1*1.1P=1,1² P
dupa a doua scumpire el devine
1,1² P+0,1*1,1² P=1,1²P (1+0,1) =1,1²*1,1P=1,1³ P
deci 1,1³P=1331
1,331P=1331
P=1331/1,331
P=1000lei pretul initial