Mario responded to an advertisement placed by Serge in a local newspaper. Serge was looking for business investments, and Mario sent him a letter on October 1st which said that he was willing to make Serge a partner in his tie-dyed T-shirt business if Serge was willing to put up $5,000. Serge received that letter on October 6th and wrote back the same day saying he would love to get involved in the business and would send Mario a certified cheque for $5,000 as soon as the bank had transferred the money from his savings account and certified the cheque. This letter was received by Mario on October 9th, and the certified cheque was sent on October 8th and received on October 12th. Meanwhile, Mario mentioned the advertisement to Sonia, and she said she would like to get into the business and would be willing to put up $8,000. Mario sent another letter to Serge, on October 4th, which Serge received on October 7th, saying Mario had changed his mind and would not be willing to have Serge as a partner.

b. Discuss whether Mario and Serge have a contract or whether Mario is free to enter into a partnership with Sonia.