How to know a given question is of permutation or combination or both combined?
For permutations, the order in which elements are arranged are important, in combinations the order does not matter.
Look for key words like 'arrangements' in permutations.
Look for key words like 'selections' or 'choose' in combinations.
e.g. In how many ways can the letters of the MONEY be arranged?
- this is an arrangement and you have 5!
e.g. 5 members are to chosen from a class of 35, a combination
- it would be C(35,5) or whatever notation your teacher uses.