Question 951884
There must be a typo, because as it is written it does not make sense.
The ages do not turn out to be whole numbers.
{{{x}}}= current age of the younger girl, and
{{{y}}}= current age of the older girl
"The current age ratio of two girls is 1:3" translates as
{{{1/3=x/y}}}<--->{{{y=3x}}} , so
{{{x}}}= current age of the younger girl,
{{{3x}}}= current age of the older girl,
{{{x+4}}}= age of the younger girl after 4 years, and
{{{3x+4}}}= age of the older girl after 4 years.
The age ratio of two girls "after four years it will be 2:3" translates as
{{{2/3=(x+4)/(3x+4)}}}<--->{{{2(3x+4)=3(x+4)}}}<-->{{{6x+8=3x+12}}}<-->{{{6x-3x=12-8}}<-->{{{3x=4}}<-->{{{x=4/3}}
That would make the younger girl's current age {{{4/3=1&1/3}}} ,
and the older girl's age would be {{{3x=3*(4/3)=4}}} .
Four years later, the older girl's age would be {{{4+4=8}}} ,
and the younger girl's age would be {{{4/3+4=4/3+12/13=16/3=5$1/3}}}
Although the ratios are as required:
{{{((4/3))/4=1/3}}} and {{{((16/3))/8=2/3}}} ,
ages are always truncated to whole number,
so {{{1&1/3}}} years after being born, a girl's age is said to be {{{1}}} ,
and {{{1&1/3}}} years after birth, she is said to be {{{5}}} years old.