3 At a call centre, \(85 \%\) of callers are put on hold before being connected to an operator. A random sample of 30 callers is selected.
- Find the probability that exactly 29 of these callers are put on hold.
- Find the probability that at least 29 of these callers are put on hold.
- If 10 random samples, each of 30 callers, are selected, find the expected number of samples in which at least 29 callers are put on hold.