A company has recently replaced their e-mail spam filter because investigations had found that the volume of

Question:

A company has recently replaced their e-mail spam filter because investigations had found that the volume of spam e-mail was interrupting productive work on about 15 % of workdays. To see how bad the situation was, calculate the probability that during a 5-day work week, e-mail spam would interrupt work:
a) On Monday and again on Tuesday?
b) For the first time on Thursday?
c) Every day?
d) At least once during the week?