Question 1210267
{{{k-m=12}}}

m climbs some floors.
x, number of floors climbed on the way

{{{k-x=x}}}, number of remaining floors to travel when traveled x floors
{{{k=2x}}}


{{{m+x=8}}}  he started at level m and traveled x floors up, and is at floor 8.


Not finishe but enough to solve.


--

No something's wrong in the above work.