Originally Posted by
UK flyer
Taxi would be easier and quicker but, if you prefer, you can take the RER Line B to Chatelet Les Halles (one stop) and transfer on to RER Line A to Charles De Gualle Etoile (2 stops) and then Metro Line 1 to Porte Maillot (2 stops). Hotel is a short walk from here. A single ticket is €1.40, cheaper if you buy a carnet of 10 tickets.
A taxi for that route and time of day will probably cost about 10 euros.
If taking public transport, wouldn't it be simpler to take the RER B to Chatelet-Les Halles and then transfer to Line 1 at Chatelet? Or is the station layout such that it makes sense to transfer to RER A first?