Question

a soil sample have a rate of percolation of 10ml/min,if 200ml of water is percolated through the sample. calculate the percolation time

Answer 1

Very easy one,
percolation rate = Quantity of water / time taken to percolate 
Percolation rate=200/40 
=5ml/minute

so , it took One minute to percolate 5ml of water.

Answer 2

percolation rate(ml/min)=amount of water(ml)/percolation time(min)

so percolation rate is given as 10ml/min

and amount of water is 200ml

so percolation time= amount of water/percolation rate

therefore, x=200ml/10ml/min

x=20min

hence, percolation time is 20 minutes

thanks,