This is a fun, cognitive stimulation activity in which participants have a lot of fun trying to solve the puzzles. I am often surprised at how well people do with solving the puzzles. My suggestion is to start with the easier ones first then move on to the more challenging puzzles. When facilitating this as a group (2-10 participants), I have them sit in front of me and I hold the sheet up so everyone can see. Alternatively, if participants can't see well, I have also drawn the puzzles on a white board. This takes more time but it works well.
Challenge yourself first to see how you do before trying it with your group (or gather some co-workers or friends to participate with you)!
The files are attached below. I've placed the answers at the end of the file. I find it works best to have the answers written on the back of each sheet so just write the answers down if you wish on each sheet (on the back). It makes it easier to have the answer handy when facilitating the group. Give lots of hints when you see the puzzle might be too challenging. You want to empower your participants so make it easier when appropriate to do so.