Araindrop falls at 200m per minute. how long will it take a raindrop to travel 6000m?

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
  
 It will take a raindrop to travel 6000m about: 
 t = 30 minutes