Objective Intention case

In a one page paper, answer the following questions:

What objective evidence was there to support the defendants$$ contention that they were just kidding when they agreed to sell the farm?

Suppose the defendants really did think the whole thing was a kind of joke. Would that make any difference?

As a matter of public policy, why does the law use an objective standard to determine the seriousness of intention, instead of a subjective standard?

It$$s $85$ degrees in July and $5$:$00$ p$.$m$.,$ quitting time. The battery in Mary$$s car is out of juice, again. Mary says, $$Arrgh$!$ I will sell this stupid car for $$50!$ Jason, walking to his car nearby, whips out his checkbook and says, $$It$$s a deal. Leave your car here. I$$ll give you a ride home and pick up your car after you give me the title.$$ Do the parties have a contract?