Tell them how they find out the solution on their own. (Give them hints, tell them to google it, whatever works...)

If they are just lazy and want you to make their work, just tell them you dont want to do it for them.

I believe if you would explain some stuff to people who are willing to learn you will benefit from it. Explaining stuff to people in an easy way is a very important skill and you should not leave out this chance to practice it completely.

Afterall if it gets too much, just give them a short answer how to find it out. (or just say "no, leave me alone" if they deserve it)

If you really want them to stop, start giving some of them false solutions.