Final answer:
No, Nero cannot set aside this contract as he does not seem to be under duress or undue influence when he made the decision to invest in Mervyn's gambling venture.
Step-by-step explanation:
No, Nero cannot set aside this contract.
Based on the given information, Nero is dependent on his nephew Melvyn for support. Mervyn advises Nero to invest in his professional gambling venture or he will no longer support him. Nero then liquidates his other investments and gives the funds to Mervyn, signing a contract in the process.
Under the principle of undue influence, a contract may be voidable if one party has exerted pressure or influence over another party to enter into the contract. However, in this situation, it does not seem that Nero was under duress or undue influence when he made the decision to invest in Mervyn's gambling venture. Therefore, Nero would not be able to set aside the contract.