definitions of above items
mistake: the contract has not gone as intended and there is some defect in the contract due to no fault of either parties.eg the seller has not said that the rice is good quality i.e. the seller has not spoken about the quality of rice
misrepresentation: the contract has gone wrong due to a false statement made innocently. eg the seller believes the rice to be of good quality but it is of low quality
coercion: forcefully selling the product.eg forcefullly selling the rice
fraud knowling making a false statement to deceive or induce the other party to enter in to the contract. .. eg.. the seller sayng the rice to be rice to be of best quality even though he knows it to be of low quality
in the above case since no statement is made by the seller and even he believed the rice to be of good quality . it is a case of mistake