2/7:4/49

To simplify the expression \( \frac{2}{7} : \frac{4}{49} \), we can rewrite it as multiplication by the reciprocal of the second fraction:

\[ \frac{2}{7} \cdot \frac{49}{4} \]

Now, multiply the numerators and denominators:

\[ \frac{2 \times 49}{7 \times 4} = \frac{98}{28} \]

Finally, simplify the fraction by dividing both the numerator and denominator by the greatest common divisor, which is 14:

\[ \frac{98 \div 14}{28 \div 14} = \frac{7}{2} \]

So, \( \frac{2}{7} : \frac{4}{49} = \frac{7}{2} \).