Digital electronics

Ok I'm stumped. I've been looking at this for 6 hours now. I've been trying to build a circuit that can count the number of switches that are on. There are 3 switches and 4 LEDs (one for each output) (0-4)

I can figure out how to make 0 and 3 light up using NORs NOTs and ANDs. But I can't figure out how to make the number 1 light up (ex. if switch 1 is on and both 2 and 3 are off or if just switch 2 is on and nothing else, or if 3 is on and nothing else)

If I can figure that out I can compute lighting up LED 2 by just polling all the inputs. The problem is I can't use any tri-input gates, I can only use gates with 2 inputs (aside from NOTs)

So basically I need to make a truth table that looks like this, using only basic gates, and no tri-input gates

1 | 2 | 3 | Q
--------------
0 | 0 | 0 | 0
0 | 0 | 1 | 1
0 | 1 | 0 | 1
0 | 1 | 1 | 0
1 | 0 | 0 | 1
1 | 0 | 1 | 0
1 | 1 | 0 | 0
1 | 1 | 1 | 0

I will pay someone who helps me find the answer or can email me the answer. I would be willing to pay $30. Post a solution here with your answer or to my email. NO JOKE.

Would "sudo usermod -G otherusergroup user" add such user to said group with out removing him for other groups?

P.S. If not I'll go back to RTFM.

Maybe for some linux implementation but this is for me to build a circuit. I found it out ages ago and just didn't realize it because I was so stupid! The boolean algebra for it is:
(1 AND (2 NOR 3)) OR (2 AND (1 NOR 3)) OR (3 AND (2 NOR 1))
Maybe next time guys. I'm sure there'll be one...this is only lab 2!

@3 Sorry intended to post a new thread.

Using 3-input AND gates and inverters:

               ---
A -------+----|   |
B -----+-|---o| & |---+
C ---+-|-|---o|   |   |
     | | |     ---    |
     | | |     ---    |    ---
     | | +---o|   |   +---|   |
     | +-|----| & |-------| & |--- Q
     | | |---o|   |   +---|   |
     | | |     ---    |    ---
     | | |     ---    |
     | | +---o|   |   |
     | +-----o| & |---+
     +--------|   |
               ---

WHAT IS THE OUTPUT OF AN EXCLUSIVE OR (XOR) GATE?

HOW CAN i USE NAND (THE UNIVERSAL GATE) TO CREATE AN XOR GATE?

Good Luck OP, this kind of thing is horrible until you get it.

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