Mo2men wrote:
Dear
GMATGuruNY,
1- Could the negations of 'C' consider STRENGTHENING the conclusion?
Not necessarily.
The negation of C is indicates that commercial traffic constitutes up to 50% of today's traffic.
If commercial traffic constitutes only 0.1% of today's traffic, then the conclusion is weakened.
If commercial traffic constitutes 50% of today's traffic, then the conclusion is supported.
The correct negation must clearly invalidate the conclusion.
Since the negation of C does not accomplish this goal, eliminate C.
Quote:
2- Could the negation of 'D' be
Commercial vehicles have a low risk of becoming involved in accidents.
or
Commercial vehicles do not have a greater risk of becoming involved in accidents.
3- In either case, Does negation of 'D' WEAKENING the conclusion? So 'D' could be an assumption. Does not the argument use the commercial vehicles less than 2 tons to conclude that it is responsible for traffic and hence accidents?
Thanks
The correct negation is the second version:
Commercial vehicles do not have a greater risk of becoming involved in accidents.Here, it is possible that commercial vehicles pose the same risk as noncommercial vehicles.
Implication:
Banning commercial vehicles that weigh more than 2 tons could reduce the number of accidents, leaving the conclusion of the argument intact.
Since the negation of D does not invalidate the conclusion, eliminate D.
E, negated:
Higher traffic congestion does not lead to higher risk of accidents.
This negation invalidates the conclusion that
a reduction in traffic will reduce accident rates in the city.
Since the negation of E invalidates the conclusion, E is an assumption: a statement that MUST BE TRUE for the conclusion to hold.
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