If I had 3 million MWK, I could go to Mzimba and buy 200 tins of maize at 12,000 MWK per tin. That would cost me 2,400,000 MWK in total. That leaves me with 600,000 MWK remaining, which I could use for transport. I would then take the maize to Likoma and sell each tin for 22,000 MWK. So, 200 tins x 22,000 MWK = 4,400,000 MWK in sales. If I subtract the buying cost from the sales, I would make a profit of 1,400,000...