Plz answer these questions by keeping in view the concept of valid contracts.

Keeping in view the requirements of a valid contract, please answer the following questions; (Marks=10) Case 1 The producer of a medicinal 'smoke ball' advertised in the print media and social media that anyone who bought and used the ball in proper way and still contracted influenza would be paid a 500 OMR reward. Miss Ayesha used the ball as per directions and did catch influenza. When she approached the producer, they claimed that there was no enforceable contract because Miss Ayesha had never notified the company that she accepted its offer. Questions Can Miss Ayesha go to a court of law and claim reward from the company? Why or why not? Is the contract in this case enforceable by law or not? Case 2 Mr. Ali offers to sell his poultry farm to Mr. Hassan for 5000 OMR. Mr. Hassan made a counter-offer, and offered 4500 OMR for the farm. Mr. Ali rejected this proposition. Later, Hassan came back and said that he now accepted the original offer of 5000 OMR. Mr. Ali rejected it. Question Can Hassan go to a court of law to enforce the original contract? Why or why not? Case 3 Umar applied to a company to buy some shares in April and paid a deposit. He didn't hear anything from company until November when company sent him a letter of allotment as acceptance and a request for the balance. By this time, Umar had changed his mind and no longer wanted the shares. Question Is Umar bound to buy the shares? Why or why not? Case 4 A mother and her three grown-up children lived together in a house. One of the son did some expensive decoration in the house and later the other two children promise pay towards the decoration costs and signed a document to this effect. Question Was the promise enforceable by law? Why or why not? Case 5 Mr. Usman owed money to Mr. Hamza and Mr. Ali. He knew that Hamza and Ali were facing some financial problems and desperately needed the money. Usman offered to pay a smaller sum to be accepted in full and final payment of the whole amount. Further, Usman stated that if it was not accepted, they will get nothing. Both Hamza and Ali reluctantly accepted the smaller sum. Question Can Hamza and Ali sue Usman for the remaining amount