From your Part A, you know the probability of X being less than -4.2 for one pipe is 0.08. In d, you are now considering 60 lengths and also told to approximate.
Hence you can represent this as a binomial distribution Z~B(n,p) where n would be 60 in this case and p being the probability of P being less than -4.2.
You are told to approximate hence you can use the Poison Distribution to approximate this distribution where your mean would be n.p so 4.8 in this case. Hence now using the Poison Distribution, find the probability of it being less or equal to 2