In my 3rd ed book, there is a table of CR against the number of monsters a party can fight based on their level. In 5e I cannot find this table. There is some mention of encounters being based on the total exp of the stuff they are fighting but it is just a couple of sentences. However this would make the CR stat in the MM redundant.
Can I re-use the table from 3rd ed or is there a new formula for using the CR in 5e? Or am I missing something completely?
Also, what is the range of CR that they can fight, for example, if the party are found to be able to kill a monster of CR 5 by whatever calculations are used, can they kill a monster of CR 6 or 7 with great difficulty? I seem to recall 3rd ed said you'd expend a certain percentage of resources but I cannot find this in the DMG for 5th edition.
Edit: Page 82 of the Dungeon Master's Guide talks about designing an encounter, but it says nothing about CR, it only talks about creating encounters based on experience.