Water is pumped at a rate of 6 l/h. how long will it take to pumo 14 l/h

I think you meant:  "Water is pumped at a rate of 6 L/H. How long will it take to pumo 14 L?"

If that's the case, then here's what you'll do:

 14 L
= 7/3 hours, or 140 minutes.
 6 L/H