The <em>rate of</em><em> </em><em>change</em><em> </em>[<em>slope</em>] of the graph is 35, and for every twoblocksyou <em>horisontally</em> move represents seventyblocks<em>vertical-wise</em>, therefore an ELEVENTH block would require you to split 70 in <em>half</em>, giving you 35, then add this to 350 to get 385.