Unlike Resident Evil 2, Resident Evil 3 has very few puzzles and they are quite simple. In case you encounter any difficulties, here are all the solutions.
This is not really a puzzle, as you only need to find three precious stones to insert into the clock. However, knowing the location of these stones can be helpful. You don't need to carry them with you. Store them in the item box at your earliest convenience. Later, when you return to the metro station, you can simply retrieve them from the box located near the clock.
Item locations:
Inserting all three stones will reward you with: a grenade, a shotgun stock, and a hip pouch.
The essence of this puzzle is to lay out the correct route. The departure point is Redstone Street, and the destination is Fox Park. The first column on the control panel represents the station names, only the first two letters are used. Refer to the map and set the stations towards Fox Park. The second column with numbers indicates the track number the train will arrive on. Choose only the open paths.
The solution is as follows:
In the room where you need to synthesize the vaccine, there will also be a small puzzle. Combine the two components you found earlier in your inventory and insert them into the apparatus. You need to ensure that all three columns show a green level.
Insert values from left to right: Mid, High, Low.