It will take 5 hours to pump 60000L of water using 9 pumps
Data;
Rate = Time * number of pumps
[tex]\frac{a}{3*10} = \frac{60000}{40000}\\ \frac{a}{30} = \frac{6}{4} \\a = 45[/tex]
But since we've established the equation above, let's substitute the values and solve for the time required to pump 60000L into the dam using 9 pumps as compared to 10 pumps. We can easily do this by calculating the rate of the pump.
Rate = time * number of pumps
[tex]45=x*9\\x = \frac{45}{9} \\x = 5 hours[/tex]
It will take 5 hours to pump 60000L of water using 9 pumps
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