Self-study
In a large residential building, there is a rule that no pets are allowed. █ █████ ██ ███ ██████ █████ ██ ██████ ████ ████ ███ ███████ ███ █████████████ █████████ ████████ ██ ███ ████████████ ███████████ ██████ ████ ████ ██ █ █████ ██ ███████ ███ ██████ ███ ██████████ ██ ██ ███████ ██ ███ ███████ ██ █ ████████ ██ ██████ █ ████ ████ ███ ████████ ██████ ██ ███ ██ █ ████████ ████ ██ ███ ███ ███████ ██ ███ █████████ ██ ███████ ████ ███ ███ ██████ ████ █████ ████ ██ █████ ████████ ██ ███ ████████ ██ ███ ████████
Argument Summary
We're told that a residential building has a rule banning pets, and that a group of pet lovers living in the building failed to get the rule changed. The stimulus then explains the process for changing the rules in the building: tenants who want to change a rule have to get signatures from 10 percent of the building's tenants, after which their proposal will be put to a majority vote. The stimulus then concludes that the pet lovers' petition must have been voted down by a majority of tenants.
Notable Assumptions
The stimulus concludes that since the pet lovers' proposed rule change wasn't implemented, they must have been voted down by a majority of tenants. This assumes that a vote happened in the first place. But remember that the stimulus doesn't say a vote is guaranteed. It says a vote on a rule change occurs only if 10 percent of tenants sign the petition:
vote → 10 percent sign
It's possible the pet lovers' proposed rule change wasn't implemented because they couldn't get enough signatures and never got to the voting stage. But since the stimulus assumes there was a vote, the stimulus necessarily assumes the pet lovers got at least 10 percent of tenants to sign their petition.
15.
The argument depends on which ███ ██ ███ █████████ ████████████
a
The pet lovers █████████ ██ █████████ ███ ██████████ ██ ██ ███████ ██ ███ ███████ ██ █████ █████████
This is correct. The stimulus assumes that a vote occurred on the pet lovers' rule change proposal, and it was voted down by a majority of tenants. But for a vote to occur in the first place, a petition must have 10 percent of tenants' signatures. So the stimulus assumes that the pet lovers succeeded in getting 10 percent of tenants to sign their petition.
b
The signatures of ████ ████ ██ ███████ ██ ███ ███████ ████ ████████ ██ ███ ███ █████████ █████████
This is the opposite of what the stimulus assumes. If the pet lovers failed to get 10 percent of tenants' signatures on their petition, then there wouldn't have been a vote on their petition to begin with, so it would have been impossible for a majority of tenants to vote down the proposal, as the conclusion states. Since the stimulus assumes the petition was voted on, it necessarily assumes the pet lovers got 10 percent of tenants to sign.
c
Ninety percent of ███ ███████ ███ ███████ ████████ ███ ████ ██████████ █████
Nothing in the stimulus suggests this is true. It's true the conclusion says that a majority of tenants voted against the proposal, but a "majority" doesn't have to be 90 percent. The 90 percent figure comes from assuming that if the pet lovers got 10 percent of tenants to sign their petition, then 90 percent must have refused to sign because they were against changing the rule, which doesn't follow.
d
The support of ██ ███████ ██ ███ ███████ ███ █ ████ ██████ ███████ ████ ███ ████ ██████ ████ ██ ████████
The stimulus doesn't assume this. The stimulus says obtaining signatures from 10 percent of tenants is necessary for a petition to be put to a vote, but that doesn't ensure that a rule change will be adopted.
e
The failure of ███ ███ ██████ ██ ██████ ███ ██████████ ██ ██ ███████ ██ ███ ███████ ██ █████ ████████ ███ █ ████ ██████ ███████ ████ ███ ████ ██████ ████ ██ █████ ████ ██ █ ████████ ██ ███ ████████
The stimulus never says that a petition that fails to receive 10 percent of tenants' signatures will be voted down by a majority of tenants. On the contrary, it says that a petition that doesn't receive 10 percent of tenants' signatures won't be voted on in the first place, because receiving 10 percent of tenants' signatures is a necessary condition for a petition to be put to a vote.