x= capacitatea vasului
[tex] \frac{2}{5} x - \frac{1}{4} \times \frac{2}{5}x = 75 [/tex]
[tex] \frac{2}{5} x - \frac{2}{20} x = 75[/tex]
[tex] \frac{2}{5} x - \frac{1}{10} x = 75[/tex]
[tex] \frac{4x}{10} - \frac{x}{10} = 75[/tex]
[tex] \frac{3x}{10} = 75[/tex]
[tex]3x = 75 \times 10[/tex]
[tex]x = \frac{75 \times 10}{3} [/tex]
[tex]x = 250[/tex]
Raspuns: 250 l