Hey,
I can't get the suitcase to open. I've found the math book and the cassette tape, and I've tried about every combination I could think of. At one point Kathy even said that I'm overthinking and shoudn't do any math...
Any tips?

Did you let her think about all the things you are carrying? Using all options you get is a good idea in general.

For anybody who's looking for the solution:

http://steamcommunity.com/app/370910/discussions/0/357284767239794235/

Thanks Laberbacke!

I am also stuck there but I don't want to read the solution - yet. Can you give another hint? I've let her thought about every item I am carying. I also know

3 red roses, 1 blue violet, 2 yellow tulips.

I have three sides in the book but which number should I pick? Or do I have to multiply them? Is the R,V,T (roses, violet, tulips) imprtant for the solution? I am so stuck here and request another hint before destrying the puzzle by reading the solution. Thank you.

Edit: Nevermind - I just figured it out :)

Well, I'm quite pleased with myself for actually figuring this out on first try.

Without much hope, I just tried the simplest possible approach, and was surprised that was the actual solution. So, I guess there's something to be said for not overthinking things ;)