Hello there. To solve this question, we have to determine which of the 5 types of sampling was used and decide whether it is quantitative or not, discrete or continuous if positive.
Okay. First, we analyze what is going on with this case:
The airline wants to survey some of its passengers and it chooses ten flights to survey every passenger about their satisfaction.
In this case, it is not a random sampling, since every passenger is being surveyed.
Now, we also say that it is not a systematic sampling because we're not counting off any elements of the list. Think as if we're labelling each passenger with a number and choosing only the passengers with a certain number, say 6.
Since the airlines are surveying each and every passenger, this is not the case.
Next, we decide if it is by convenience sampling. Again, not the case because the convenience sampling works as follows: the first person the airlines would run into.
Since every passenger is being surveyed, it is not the answer.
Now, the most difficult ones to decide: cluster or stratified.
But in fact, not that difficult: we have a cluster when we divide the population to be surveyed into blocks or groups called clusters and it is usually geographically.
Stratified sampling works basically the same as clusters, but this time we divide the population by some characteristics into two or few more groups called strata and this characteristics might be male or female, for example.
Since in this case we're sampling passengers from an airline company, we say that it best fits the definition for a stratified sampling.
Now, we decide if it is quantitative.
Notice that the answers are not said to be numbers, since they are asking about their satisfaction. Hence we cannot assume it is quantitative, nor discrete and continuous.
Otherwise, it would be discrete, since the values (we say rating) would be numbers from maybe 0 to 10.