Odpowiedź :
2500 zł------100%
x zł--------120%
x=(2500·120)/100
x=300000/100
x=3000 zł
==================
3000 zł-----100%
x zł----------90%
x=(3000·90)/100
x=270000/100
x=2700 zł
2500 zł------100%
x zł--------120%
x=(2500·120)/100
x=300000/100
x=3000 zł
==================
3000 zł-----100%
x zł----------90%
x=(3000·90)/100
x=270000/100
x=2700 zł