A fraction equivalent to $\frac{8}{12}$ is

 

If $\frac{18}{90}=\frac{30}{k}$, then the value of $k$ is _____

If $\frac{105}{85}=\frac{21}{k}$, then value of $k$ is _____.

If$\frac{k}{14}=\frac{30}{12}$, then value of $k$ is _____

If $\frac{5}{k}=\frac{35}{84}$, then the value of $k$ is _____

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$\frac{2}{6}=\frac{}{3}$, If the answer is $k$, then write the value of $k$_____.