Question 171408
well the answer is 9 

: remember the middle rung can only be counted once so we need to account for that
:
if x is the total distance from one rung to the other
:
(1/2)x=3-5+6+1/2........the 1/2 is so that the middle rung is counted once
:
x/2=4.5
:
{{{x=9)}}}steps