The public transport tickets are 32 Czech crowns (90 minutes) or 24 Czech crowns (30 minutes). You may buy it in kiosks or through the coin machine at many stops.
Please validate your tiket as you enter the metro, bus, or tram. Please note that there are no barriers as you enter the metro – so keep an eye out for the posts that mark the entrance of the metro – and where you need to validate your tiket.