Bunuel wrote:
If Paula drove the distance from her home to her college at an average speed that was greater than 70 kilometers per hour, did it take her less than 3 hours to drive this distance?
(1) The distance that Paula drove from her home to her college was greater than 200 kilometers.
(2) The distance that Paula drove from her home to her college was less than 205 kilometers.
Statement One Alone:
The distance that Paula drove from her home to her college was greater than 200 kilometers.
We don’t have enough information to determine whether it takes her less than 3 hours to drive to school. For example, if the distance is 320 km, and her speed is 80 kmph, then it takes her 4 hours to drive to school. However, if the distance is 220 km, and her speed is 80 kmph, then it takes her 2.75 hours to drive to school.
Statement one alone is not sufficient.
Statement One Alone:
The distance that Paula drove from her home to her college was less than 205 kilometers.
We do have enough information to determine whether it takes her less than 3 hours to drive to school. Let’s say the distance is exactly 205 km and her speed is exactly 70 kmph. Then it takes her approximately 2.93 hours to drive to school. However, since the distance is less than 205 km and her speed is greater than 70 kmph, it will definitely take her less than 2.93 hours (and hence less than 3 hours) to drive to school.
Statement two alone is sufficient.
Answer: B