To get to work, a commuter must cross train tracks. The time the train arrives varies slightly from day to day, but the commuter estimates he'll get stopped on about 15% of work days. During a certain 5-day work week, what is the probability that he
a) Gets stopped on Monday and again on Tuesday?
b) Gets stopped for the first time on Thursday?
c) Gets stopped every day?
d) Gets stopped at least once during the week?