p= pretul initial
p+p*10/100 = p+p/10 = 11p/10 = pretul dupa scumpirea cu 10%
11p/10+(11p/10)*(15/100) = 2277, pretul dupa a doua scumpire
11p/10+(11p/10)*(3/20) = 2277 ; 11p/10+33p/200 = 2277, numitor comun 200
220p+33p=445400 ; 253p=445400 ; p = 445400/253 = 1800 lei