Answer:
Step-by-step explanation:
One pump will fill 200l in 20 minutes
So the rate of filling per pump will be 10l/minute (200/20)
Let the number of minutes it will take to fill the 600l be x minutes
Now, since the rate of filling per pump is 10 l/minute
Then in x minute, they would have filled 10l/minute * x = 10x liters
So it is now this 10x liters that will be equal to 600
To find x, we simply divide
10x = 600
x= 600/10
x = 6 minutes