4. In relation to the law of contract, explain the legal principles applicable in the following situations stating whether a contract exists or not.

Mjomba sees a suitcase in a shop window with a price label of Ksh. 5,000. He goes into the shop to buy the suitcase. He gives 5,000 to the cashier but he is told that the wrong price tag had been attached and that the correct price is Ksh. 6,000. Mjomba insists that he bought the suitcase for Ksh. 5,000. Advice Mjomba.