Self-study
City official: Landowners must clear the snow from the sidewalks along the edge of their property by 24 hours after the end of a snowstorm. ███ ████ ███ ███ █████ ██ █████ ███ ████████ ████ ██ █████ ███████ ████ ████ ██ █████ █████ █ ███████████ ████ ███ ████████ ██ ████ ███ ██ ████ ████ ███ █████████ ███ ███ ████████ ███ ██████████ █████ █████████ ████ ███ ████ ███████ ██████ ██ █████ ██ ███ ███ ██ █ █████████ ████ ███████ ██████████ █████ ██████ ██████ ██ █████ ██████ ███ ██████████ ███ ███████████ ███████████ ██████████████
Summary
The stimulus can be diagrammed as follows:
Notable Valid Inferences
If the sidewalk is covered by snow after 24 hours, the city might bill the landowner for the cleaning.
21.
If all of the official's ██████████ ███ █████ █████ ███ ██ ███ █████████ ████ ██ █████
a
If the city ██████ █ ████████ ██ ████ ██ █████ █████ ███ ███ ██ █ ██████████ ███ █████ ████ ██ ██████ ███ ███ ███████ ███ ████ ███████ █ █████████
Must be true. As shown below, if the city clears the sidewalk, the owner will be billed. If the sidewalk hasn’t been cleared within 48 hours, then the owner will receive a citation.
b
All landowners who ████ ██ █████ █████ █████████ ██ ██ █████ █████ ███ ███ ██ █ █████████ ████ ██ ██████ ██ ███ ████ ███ ████ ████████
Could be false. If the sidewalk is covered after 24 hours, the city has the right to clear the sidewalk, but this isn’t a guarantee that the city will actually do it. It could be the case that the city doesn’t clear someone’s sidewalk (and that they wouldn’t be billed).
c
All sidewalks in ███ ████ ████ ██ ███████ ██ ████ ██████ ██ █████ ██ ███ ███ ██ █ ██████████
Could be false. If the sidewalk is covered by snow after 24 hours, the city has the right to clear it, but the city isn’t required to do so. If the sidewalk isn’t cleared after 48 hours, the landowner is cited, but this doesn’t guarantee that the sidewalk will be cleared.
d
Nearly all landowners ███ ██ ███ █████ █████ █████████ ██████ ██ █████ █████ ███ ███ ██ █ █████████ ████ ██ ██████
Could be false. The stimulus does not provide information to support inferences about quantities of landowners; we don’t know what happens to “nearly all” landowners. It could be the case that these landowners’ sidewalks were cleared by the city before 48 hours.
e
Landowners who can ███████████ ███████████ █████████████ ████ ███ ██ ██████ ██ ███ ████ ███ ████ ███████ ████████
Could be false. The bill comes from performing the service of clearing the sidewalk; it is still the case that if these landowners receive the service of the city clearing their sidewalks, then they will be billed.