Liza Doolittle purchases a market stall from Len Turnip, who is retiring from his fruit and vegetables business. She initially invested $2,500. The cost of the stall is $1,800.She also purchases some flowers and potted plants from a trader in the wholesale market, at a cost of $650. On 3 July Liza has a very successful day. She sells all of her flowers and plants for $900 cash. Since Liza has sold goods costing $650 to earn revenue of $900.