Data Sufficiency

If Car X followed Car Y across a certain bridge that is 1/2 mile long, how many did it take Car X to travel across the bridge?

1) Car X drove onto the bridge exactly 3 seconds after Car Y drove onto the bridge and drove off the bridge exactly 2 seconds after Car Y drove off the bridge.

2) Car Y traveled across the bridge at a constant speed of 30 miles per hour.

The OA is C

Source: GMAT Paper Tests