Consider whether a valid contract has been formed in the following circumstances

a) Iraj sees the following advertisement in his local newspaper: "For Sale: Rose Bushes only 12.99 for five. Hurry-limited supplies. Send cheque to Beautiful Gardens Ltd., PO box 123 Iraj sends a cheque but is told the bushes are sold out

b) Dave writes to Peter, You mentioned that you would like to buy my red sports car. You can have it for 5,000. If you want it let me know by the end of the week. The following day Dave sells his car to Jane Peter learns of the sale and immediately tells Dave he accepts his offer.

c) Mary sent out a circular to all interested businesses in her area offering for sale her fleet of com- pany cars for which tenders were invited. Jane's tender turned out to be the highest but Mary has refused to sell her the cars.

d) Strait and Co, a manufacturer of vitamin pills, states in an advertisement that the regular use of its Vito' pills will increase a user's energy levels in two weeks. Slouch takes 'Vito' pills every day for two weeks but notices no improvement in his energy.

e) Penelope writes to Quentin offering to buy his car for 2,000 and says that if she has not heard from him within a week she will assume that he has accepted. A week elapses and Penelope has heard nothing from Quentin

f) On Monday Teresa sends a fax to Ursula offering to sell her diamond necklace at a knock down price of 10,000 for a quick sale. Ursula sends a letter back the same day accepting the offer. On Tuesday, before Ursula's letter arrives, Teresa agrees to sell the necklace to another person.

g) James offers to sell his laptop to David for