( 1 ) THIS petition has been Filed by the petitioners impugning the Demand Notices issued by Delhi Development Authority during the period 22/8/1991 to August 31,1991 and for issuance of a writ of mandamus directing the respondents to revise the cost of the tenements on the principles of "no Profit No Loss" basis as applicable to the tenements allotted to EWS (Economically weaker section) category. It is alleged in the writ petition that Delhi Development Authority, respondent No. 2 is responsible for constructing and for allotment of tenements to. various categories of registered persons including the EWS and according to the policy and practice of the respondents the cost of such flats are subsidised from the profit earned from disposal cost of houses allotted to middle and higher income groups of the Society and other sources. The registration scheme which concerns the petitioners was opened from 21/11/1985 to 30/12/1985 which period was extended subsequently. The details of the scheme as well as the averments made by the petitioners are incorporated in paragraphs 7 to 16 of the writ petition which may be reproduced as follows:

"7. That in clause I of the brochure