Question 1064569

Kathy stood on the middle rung of a ladder. She climbed up 2 rings, moved down 3 rings and then climbed up 7 rings. Then she climbed up the remaining 2 rings to the top of the ladder. How many rings are there in the whole ladder? 
<pre>Let number of rungs be R
Standing on the middle rung, there are equal number of rungs above her and below her
Thus, she’s standing on the MEDIAN rung, or the {{{(R + 1)/2}}} rung
We then get: {{{(R + 1)/2 + 2 - 3 + 7 + 2 = R}}}
{{{(R + 1)/2 + 8 = R}}}
R + 1 + 16 = 2R ------ Multiplying by LCD, 2
17 = 2R – R
R, or number of rungs = {{{highlight_green(17)}}}