8. In two weeks three cows eat all the grass on two hectares of land, together with all the grass that regrows there during the two weeks. In four weeks, two cows eat all the grass on two hectares of land, together with all the grass that regrows there during the four weeks.
How many cows will eat all the grass on six hectares of land in six weeks, together with all the grass that regrows there over the six weeks?
(Assume: - the quantity of grass on each hectare is the same when the cows begin to graze,
- the rate of growth of the grass is uniform during the time of grazing,
- and the cows eat the same amount of grass each week.)