Suggest again the computer security system from Problem 4.3. Approximately 10% of the attempts to illegally access the computer make it past the first security level.
(a) What is the probability that there will be exactly three attempted illegal entries that successfully make it past the first security level during the next week?
(b) It is now 6AM Monday morning. The most recent security attempt that success- fully made it past the first security level occurred at midnight last night. What is the probability that no illegal attempts make it past the first security level during the time period from now (6AM Monday morning) through 6PM Friday?