Answer:
1 and 2
Explanation:
The sample is not a representation of the population, the population of students in colleges are high thus at least 10% of the population should be surveyed, this gives a better representation of the entire population.
The survey will also be biased as she stands outside the engineering building only and other students not belongings to this faculty might not be able to participate, thus the responses she will get will tend towards the favourable direction for the engineering students and will not reflects the entire students including non engineering students opinions on their college class schedule.