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题库 / Prep2007E1-DS-46
How many hours did it take Helen to drive from her house to her parents' house?
(1) Helen's average speed on this trip was 72 kilometers per hour.
(2) If Helen's average speed on this trip had been 8 kilometers per hour greater, it would have taken her 1 hour less.
Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
EACH statement ALONE is sufficient.
Statements (1) and (2) TOGETHER are NOT sufficient.
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(1)(2):
72x=80(x-1)