Kate buys three chocolate bars per week at a price of $1.25, five at a price of $1, and seven at a price of 75 cents. Her friend Carlo buys five chocolate bars at a price of $1.25, eight at a price of $1, and 11 at a price of 75 cents. a. If these two friends are the only consumers in the market for chocolate bars, what are three points on the market demand curve?