varog mult repede multttttttttttttttttttt tttttttt ttttttttttt ttttttttttt ttttttttttt ttttttttttt ttttttttttt ttttttttttt

x - butoi de 10 litri
y - butoi de 20 litri
x+y = 250
10x+20y=3500
x=250-y
10(250-y)+20y=3500
2500 - 10y +20y = 3500
10y = 1000
y = 100
x = 250-100 = 150