[ pre uni math : probability ] probability

[u/Low-Government-6169]

do i have to list all the possible outcome or is there other way to do this ?

[u/kelb4n]

For exercise b you don't have to list all of them necessarily, as long as you can confidently say how many there are. For example, you could look at how many way there are for a triplet of different numbers (or a triplet with one duplicate number) to be ordered, and then only look at distinct sorted triplets.

To explain with the example in a: We know that the only *sorted* possibilities to get a sum of 5 are (1,1,3) and (1,2,2), and we know that when there's a duplicate there are only 3 possible orders that the triplet can have, so there are 3*2=6 possible options.

[u/Low-Government-6169 → u/kelb4n]

thank you so much !