Question 1085968


 let age of a girl be {{{x}}} and the age of her grandmother {{{y}}}

if the age of a girl in months is equal to the age of her grandmother in years, 

{{{12x=y}}}.....eq.1

If the difference between their ages is {{{66}}} years, 
 {{{y-x=66}}}
 {{{y=66+x}}}.....eq.2

from eq.1 and eq.2 we have 
{{{12x=66+x}}}

{{{12x-x=66}}}

{{{11x=66}}}

{{{x=66/11}}}

{{{x=6}}}->The age of a girl

{{{y=66+x}}}
{{{y=66+6}}}

{{{y=72}}}->the age of her grandmother 

{{{12x=12*6=72}}}->The age of a girl in months which is equal to the age of her grandmother in years