Question 1089004

increasing {{{20}}} by {{{P}}} percent:{{{20+20*P}}}%
decreasing {{{60}}} by {{{P}}} percent:{{{60-60*P}}}%

yields the same result:

{{{20+20*P}}}%={{{60-60*P}}}%
{{{60P+20*P}}}%={{{60-20}}}
=>{{{80*P}}}%={{{40}}}
=>{{{P/100=40/80}}}
=>{{{P/100=0.5}}}
=>{{{P=50}}}
So, {{{P=50}}}%  of {{{70}}} is: {{{70*(50/100)=7*5=35}}}