In the study of consumer’s behaviour we find that, starting from Marshall to Hicks, everybody assumes that the consumer will behave rationally. In other words behaviour of an individual consumer must satisfy a regularity which can be explained logically. They have based their logic in the form of utility maximization. That means an individual consumer is motivated to maximize his/her utility and his/her every purchase decision is based on the principle of utility maximization. Therefore utility maximizing behaviour is treated as rational behaviour to Marshall and Hicks. Such straight forward correspondence between rationality and utility maximization is regarded as core of the analysis of consumer’s behaviour. Even Samuelson’s Revealed Preference Theory implicitly considers that a commodity bundle is chosen by an individual consumer as it yields maximum utility to him/her. All the conventional approaches to the theory of consumer’s behaviour assume that consumer is synonymous to buyer. All of them identified consumer as a buyer and no consumer faces the problem of indivisibility in respect of their consumption. With this back ground in mind our present paper seeks to explore whether the concept of rationality is confined only within utility maximization or it has a wider connotation. . Section-I of this paper contains Introduction. Section-II deals with Analytical framework and Section-III contains Analysis of the problem. Section IV is devoted to Findings and Conclusion