Question 1096710
The ratio of the ages of two sisters is 4:3 ,
 the younget sister is three years older than the younger one .
 how old is the younger sister 
:
let x = the multiplier
then
4x = the age of the older sister
and
3x = the age of the younger
:
"the youngest sister is three years older than the younger one"
this really does not make sense, assume it is:
"the oldest sister is three years older than the younger one"
4x = 3x + 3
4x - 3x = 3
x = 3 is the multiplier
therefore
4(3) = 12 yrs is the older sister
and
3(3) = 9 yrs is the younger sister