by terence.battle1 Mon Apr 25, 2011 12:55 pm
6 miles at 5280 = 31,680 to turn it into terms of feet.
Option 1 says greater than 16 feet per second. Therefore he traveled a minimum of 961 feet per minute. For 30 minutes we know the travel was short of 6 miles but since we don't know if he traveled 20 feet per second it's insufficient.
Option 2 says less than 18 feet per second. Applying same approach you get 18 x 60 - 1080 feet per minute. For 30 minutes you will come up with 32,400 which is greater then six miles however we know he was slower then 18 but not how much slower he was. So insufficient.
Taking both options together we know he traveled between 16 and 18 non inclusive. This still does not tell us if he traveled 16.1 or 17.9 and each would yield a value either greater or less than the target. So option E.