[tex]p\%=\dfrac{p}{100}\\\50\%=\dfrac{50}{100}=\dfrac{1}{2}\\\\50\%\ of\ 70\to\dfrac{1}{2}\cdot70=35\\\\30\%=\dfrac{30}{100}=\dfrac{3}{10}\\\\30\%\ of\ 80\to dfrac{3}{10}cdot80=24[/tex]
[tex] \begin{array}{ccc}24&-&100\%\\35&-&p\%\end{array}\ \ \ \ |\text{cross multiply}\\\\24p=35\cdot100\\\\24p=3500\ \ \ \ |:24\\\\p=\dfrac{3500}{24}\\\\p=\dfrac{875}{6}\\\\35\ is\ \dfrac{875}{6}\%\ of\ 24\\\\x\%=\dfrac{875}{6}\%-100\%=\dfrac{875}{6}\%-\dfrac{600}{6}\%=\dfrac{275}{6}\%=45\dfrac{5}{6}\%\approx46\% [/tex]
