let's pick a number, hmmm say number "a", and let's increase it twice by 5%.
[tex]\begin{array}{|c|ll} \cline{1-1} \textit{a\% of b}\\ \cline{1-1} \\ \left( \cfrac{a}{100} \right)\cdot b \\\\ \cline{1-1} \end{array}~\hspace{5em}\stackrel{\textit{5\% of a}}{\left( \cfrac{5}{100} \right)a}\implies 0.05a~\hfill \stackrel{a+0.05a}{1.05a}[/tex]
[tex]\begin{array}{|c|ll} \cline{1-1} \textit{a\% of b}\\ \cline{1-1} \\ \left( \cfrac{a}{100} \right)\cdot b \\\\ \cline{1-1} \end{array}~\hspace{5em}\stackrel{\textit{5\% of 1.05a}}{\left( \cfrac{5}{100} \right)1.05a}\implies 0.0525a~\hfill \stackrel{1.05a+0.0525a}{1.1025a} \\\\[-0.35em] ~\dotfill\\\\ 1.1025a~~ - ~~a~~ = ~~\stackrel{difference}{0.1025}\qquad \qquad \stackrel{\textit{converting to \%}}{0.1025\cdot 100}\implies \stackrel{\%}{10.25}[/tex]
