The first thing you should know is that by definition:
d = v * t
Where
d: distance
v: speed
t: time
We then have to clear the time:
t = (d) / (v)
Substituting the values:
t = (6000) / (200)
t = 30 minutes
Answer:
It will take a raindrop to travel 6000m about:
t = 30 minutes