Data Sufficiency

Source: Veritas Prep

Bill rides his bike to work in the morning on a route that is 18 km long. Did Bill take longer than 40 minutes to get to work this morning? (1 km = approximately 0.6 miles)

1) Bill's average speed on the trip this morning was greater than 18 miles per hour.
2) Bill's average speed on the trip this morning was less than 20 miles per hour.

The OA is A

18 miles per hour - the time taken 36 minutes. So time will be less than 36 minutes for any speed more than 18.

Speed Less than 20 means it can be anything.

Say 10.8 miles per hr - so the time taken will be 60 minutes - not sufficient.

Therefore, __A__