For the following question I figured that the expected time between successive arrival is the mean = 1/10 per hour (or 1 per 6 minutes). My question is regarding the second part; does the fact that the last driver has arrived 15 minutes ago effect any calculations? if not will the answer simply be P(x>0.25)=1-P(x<=0.25)=0.024? (P is Cumulative Distribution Function)
If the information given regarding the last drive-up is relevant could you provide me with a hint?