There is a law made that every man that keeps sheep shall for every 10 sheep, sow one acre of ground and for his allowance in sheep pasture there is appointed for every 4 sheep one acre of pasture....

There is a law made that every man that keeps sheep shall for every 10 sheep, sow one acre of ground and for his allowance in sheep pasture there is appointed for every 4 sheep one acre of pasture. Now there is a rich sheep master who has 7000 acres of ground and would gladly keep as many sheep as he might by that law. How many sheep shall he keep?