There are a number of possible interpretations you could take of words which appear to indicate a private purpose trust. It could be a invalid private purpose trust; it could really be a trust for the benefit of specified persons as in Re Denley; it could be an absolute gift with a mere expression of motive; it could create a bare trust with a mere power of capital appointment for the specified purpose (i.e. the trustee can disburse money for that purpose); and so on.
What you need to do is have a paragraph or two on each section of the question. Then run through the different interpretations a court might take of what is going on; and explain why a court would be likely (or not) to favour that interpretation.
For example, c) concerns unincorporated associations. It could be a absolute gift to the members, but this is probably unlikely.
It could be a trust for the purposes of the Association. This would be a invalid private purpose trust, the money going to Sunitra.
It may be possible to understand it as really a trust in favour of specified individuals; namely the members of the club. This is a trust in favour of individuals, and so is valid, Re Denley. However, if this is the case, then when the Association dissolves the money goes back to Brinda's estate by means of a resulting trust, Re West Sussex.
Finally, there are a lot of cases in this area of law which say that trusts law doesn't have a role to play at all - it could be seen as a gift to the unincorporated Association governed by contract, Re Bucks. Under this interpretation, its all governed by contract, and so what happens to the money is governed by the Association's constitution; so it can transfer the assets to the new club.
You have to run through those interpretations and then come up with reasons why one interpretation should be favoured over another. The general tendency in unincorporated association cases these days is to favour contract law, (Re Horley Town FC is an example of this), but it isn't universal (in Davis v Richards the judge said a trusts law approach is to be favoured).
Similarly, in d) there are a number of ways you can look at it. It could be a trust for the purpose of ensuring the cats welfare which would be invalid; it could really be a trust in favour of the owners of the cats which is a trust in favour of specified people and so is not a purpose trust and is valid (there are cases which say a trust in favour of animals is really in favour of the owners); it could be a gift to the owners with a mere expression of motive. d) is looking rather like an invalid purpose trust, but it is at least arguable that it creates a trust in favour of the new cat owners.
e) is rather similar to d) in that it could be a trust for the abstract purpose of maintaining Lucy which would be invalid; but it would more sensibly be understood as simply a trust in favour of Lucy.
Do a) and b) in similar fashion....
Google for Alastair Hudson's website and listen to his podcasts on the beneficiary principle and the one on unincorporated associations.