Any notice required to be served on, or given to, any person under this Act or the rules made thereunder shall be deemed to be duly served or given:

(a) if the notice is addressed to that person and is given or tendered to him; or

(b) where that person cannot be found if it is affixed on some conspicuous part of his last known place of residence or business or is tendered to some adult member of his family; or

(c) if it is sent by registered post to that person at his last known place of residence or business.