so 12 mins to 600 feet 35 mins=1900 feet find the slope which is change in top over change in bottom (aka slope) so to find do (y1-y2)/(x1-x2) we want, per minute, so put the time as x1 and x2 x1=12 y1=600 x2=35 y2=1900 subsitutte (600-1900)/(12-35)=-1300/-23=56.5 per minute the answe ris 56.5 feet per minute or the last answer