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How to obtain 4 input or gate using 2 input gates?

  1. Sep 7, 2005 #1
    how can i obtain 4 input or gate using 2 input gates? :confused:

    any help will be appreciated.
  2. jcsd
  3. Sep 7, 2005 #2
    You have four inputs a,b,c,d.
    Run a and b in one or gate. And get output m.
    Run c and d in another or gate. And get output n.
    Run m and n in a third or gate, and you have your final output z.
  4. Sep 7, 2005 #3


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    Doing the problem for him doesn't help him learn. :tongue2: For example, it takes away from him the possibility of figuring out on his own that he could look at the algebraic expression W or X or Y or Z, and figure out that he can group them in pairs, then turn the result into a circuit. These things are much better learned by working it out yourself than being handed the answer. :frown:
  5. Sep 7, 2005 #4
    hi. thank you. i am thinking of that way too but wouldn't that require 3 get instead of 2?
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