I________I________I-----------I 3/3=vaporul incarcat la maxim
2/3
I_____i______i______i_____I 4/4 vaporul incarcat la maxim
3/4
3/3x=4/4x
2/3x+1/3x=3/3x
2/3x+20 t=3/4 x
4x/4=2x/3+20t+x/4
4x/4-x/4-2x/3=20t
3x/4-2x/3=20t
aducem la acelasi numitor'12
9x-8x/12=20t
x/12=20t
x=12x20t
x=240 t