2/4 : 7/3 : 6/6 = 2/4 + 7/3 + 1/6 =

1.

[tex] \frac{2}{4} \times \frac{3}{7} \times \frac{6}{6} [/tex]

[tex] \frac{6}{28} = \frac{3}{14} [/tex]

2.
[tex] \frac{2}{4} + \frac{7}{3} + \frac{1}{6} [/tex]

[tex] \frac{3 + 14 + 1}{6} [/tex]

[tex] \frac{18}{6} [/tex]

[tex]3[/tex]