a) What arguments could Chen use to justify his refusal to pay John more than the originally agreed price? A valid and legally enforceable contract should consist of a offer, acceptance, intention to be bound and sufficient consideration. Accordingly, the first contract entered into by Chen and John includes John's agreement to build for Chen an extension to the house in consideration of payment of the price of the building materials on the date of completion of the contract and the labor costs of $6,000 upon execution. of the contract. First and foremost, Chen must understand that this was the original contract and that he and John were legally bound by the contract. By changing the terms of the deal, John made a counteroffer, a fact that Chen could use to justify his refusal to pay. . This is evident since John proposed a new condition in the contract by demanding payment of $10,000 or not doing the work as agreed in the original contract. A counteroffer changes the terms of the original contract and at that point, Chen had the right to terminate the contract due to John's counteroffer. In fact, it should be noted that a counteroffer does not exist if the offeree agrees to the new terms of the contract as Chen did, but Chen can use this to argue that John did not intend to be bound by the initial contract (Koffman and Mcdonald, 2007). Duress occurs in a contract when a party is forced to enter into a contract that he or she was otherwise unwilling to enter into due to blackmail, threats of causing actual harm, and threats of withdrawal from the contract upon time of the contract. time when it is urgent to do so. The two types of coercion that currently exist are physical coercion and economic coercion and Chen can use economics...... middle of paper ......n to argue that failure to complete the contract on time was due to circumstances which he could not control. Furthermore, John can argue that the June failure to complete the building was due to Chens' reluctance to accept the second offer.ReferencesBooksAdams, A. (2010). Right for business students. London, UK: LongmanKoffman, L. & MacDonald, E., (2007) The Law of Contract (6th edition): Oxford University Press, McKenDrick, E. (2005). Text of contract law. Cases and Papers (2nd Edition): Oxford University Press, CasesBank of Australia Limited v Amadio (1983) 151 CLR 447 Goldsbrough Mort & Co Ltd v Quinn (1910) 10 CLR 674, Integrated Computer Services Pty Ltd v Digital Equipment Corp (Aust) Pty Ltd (1988) 5 BPR 11,110). Smith v William Charlick [1924] 34 CLR 38The Mihalis Angelos [1970] 3 WLR 601