Explain the modes of revocation of an offer as per the Indian Contract Act, 1872.

Modes of revocation of Offer i) By notice of revocation ii) By lapse of time: The time for acceptance can lapse if the acceptance is not given within the specified time and where no time is specified, then within a reasonable time. iii) By non-fulfillment of condition precedent: Where the acceptor fails to fulfill a condition precedent to acceptance the proposal gets revoked. iv) By death or insanity: Death or insanity of the proposer would result in automatic revocation of the proposal but only if the fact of death or insanity comes to the knowledge of the acceptor. v) By counter offer vi) By counter offer By the non- acceptance of the offer according to the prescribed or usual mode vii) By subsequent illegality