Mary decided to sell her car, and on Monday 1st May, she tells her friend Joanne:

"Do you want to buy my car for $15,000? Take a few days to think about it. I need to know by the end of the week"

On Tuesday 2nd May, Joanne telephones Mary and says:

"I can't afford $15,000 at the moment, all I can afford to pay is $14,500. Will you take this for it?"

On 3rd May, Mary sells her car to Michael.

On the 4th May, Joanne calls Mary back and tells her:

"My mum has lent me $500, and now I have the full $15,000, and would like to buy the car for the price you asked for on Monday".

Mary responds and tells Joanne:

"Sorry, I sold the car to someone yesterday".