Question 997749
 the percent change when a quantity changes from {{{66}}} to {{{54}}}:

the difference is  {{{66-54=12}}}

here you need to find {{{x}}}% or  {{{x/100}}} of {{{66}}} equal to {{{12}}} 


{{{(x/100)66=12}}}....solve for {{{x}}}


{{{(x/50)33=12}}}


{{{33x/50=12}}}

{{{33x=12*50}}}

{{{x=600/33}}}

{{{x=18.18181818}}}

{{{highlight(x=18.18)}}}%=> your answer


check:

{{{18.18}}}% of {{{66}}} is:

{{{(18.18/100)66}}}

={{{(18.18*66)/100}}}

={{{1199.88/100}}}

={{{11.9988}}}....round it to whole number

={{{12}}}

{{{66-12=54}}}