If it took Carlos ½ hours to cycle from his house to the library yesterday, was the distance that he cycled greater than 6 miles? (Note: 1 mile=5,280 feet)

st(1) The average speed at which Carlos cycled from his house to the library yesterday was greater than 16 feet per second. To answer the question we need to know if the average speed given in this statement was greater than 6*2(5280/3600), as only ½ hours was travel time.
Is x=<16 when x=6*2(5280/3600), x=5280/300, x=528/30=88*6/6*5=88/5=16 3/5
we know now that speed greater than 16 implies there can be 16 and more than 16 and this is Not Sufficient, as we can travel more or less than the required.

st(2) The average speed at which Carlos cycled from his house to the library yesterday was less than 18 feet per second. By knowing what happened in st(1) we can answer this is Not Sufficient too, because we could have both possibilities.

Combining st(1&2) is also Not Sufficient as interval 16-18 allows for two possibilities.

e

6 miles in 1/2 hr means speed = 17.6 feet/sec

Statement (1) Speed > 16 ft/sec can be anywhere between 16 and 17.6...INSUFFICIENT
Statement (2) Speed < 18 ft/sec can be anywhere between 1 and 18....INSUFFICIENT

Combining (1) and (2)

It can be anywhere between 16 and 18..So Still INSUFFICIENT

(E) is the answer