Amar obtained from Bhaskar a lease of some coal bearing land ,the terms being a royalty of Rs.4 per ton of coal raised subject to minimum rent of Rs.20,000 per annum with a right of recoupment of short workings over the first four years of the lease. The following are the relevant particulars: Years Sales (Tons) Closing Stock (Tons) 2011 2,200 300 2012 3,300 500 2013 4,800 600 2014 6,000 700 2015 7,000 800