Question 974856
Helppppppppppp 
explanation and answer please 


Kathy stood on the middle rung of a ladder. She climbed up 2 rungs, moved down 5, up then climbed up 6 rugs, and up 4 more to get to the top of the ladder.

 How many rungs are there in this ladder?
<pre>Let number of rungs be R
Then middle, or median rung = {{{(R + 1)/2}}}
Moving up and down the ladder, we get:  {{{(R + 1)/2 + 2 - 5 + 6 + 4 = R}}}
{{{(R + 1)/2 + 7 = R}}}
R + 1 + 14 = 2R -------- Multiplying by LCD, 2
R + 15 = 2R
R – 2R = - 15
- R = - 15
R, or number of rungs = {{{(- 15)/(- 1)}}}, or {{{highlight_green(15)}}}