CREATE TABLE table_name_40 (number_of_electorates__2009_ INTEGER, reserved_for___sc___st__none_ VARCHAR(255), name VARCHAR(255))
Name the Number of electorates (2009 which has a Reserved for ( SC / ST /None) of none, and a Name of jahanabad?
    
SQL: SELECT MIN(number_of_electorates__2009_) FROM table_name_40 WHERE reserved_for___sc___st__none_ = "none" AND name = "jahanabad"