Doyen Constructions Pty Ltd is a multinational construction and property investment company based in Sydney. After failure to make profits from a number of construction projects with major commercial clients, it needs to sell assets to reduce its debt burden. Yidee has recently been appointed as the Managing Director of the company. Yidee's authority to dispose of assets has been capped by the board at $500,000 per individual transactions. She negotiates for the sale of a piece of land in Western Sydney to Victory City Pty Ltd, a local property development company, at $550,000 which is valued by Doyen at about $450,000. She had expected that the sale price would be reduced in negotiations and thereby, would not exceed the board's cap of $500,000 that has been imposed on her. She informs the managing director of Victory City that the current board of Doyen is unpredictable and can change the decision to sell off its assets anytime, so there is a narrow window of opportunity for Victory City to get hold of a valuable property at a lower price. Victory City accepts Yidee's asking price. The sale is completed by the exchange of letters signed by the managing directors of the two companies. When the board of Doyen hears about it, the board wants to unwind the sale of the property, as it considers the property as a key asset of the company. When Victory City finds out that Doyen is unwilling to go ahead with the contract, it demands that Doyen honours the contract that Yidee entered.

By referring to relevant statutory provisions and case laws, advise whether Doyen is bound by the contract that Yidee entered as the managing director of Doyen with Victory City.