Question 972566
b,s brother, sister;
x, more years;


{{{b=4s}}}, {{{4b=(s+x)<30}}}.


{{{4(4s)=s+x<30}}}
{{{16s=s+x<30}}}
This looks like two simultaneous statements in variables s and x.
{{{system(16s=s+x,s+x<30)}}}
{{{system(15s=x,s<30-x)}}}
{{{s<30-(15s)}}}
{{{s<30-15s}}}
{{{s+15s<30}}}
{{{16s<30}}}
{{{8s<15}}}
{{{s<15/8}}}


Sister could be between 0 years and 1 year 10.5 months, exclusive.