Hint:
There is also a game show circuit using SCR's that is about as simple as it can get, requiring just five parts plus one small SCR, one push-button, and one LED per player with no additional logic.
Even the single LED current limit resistor is shared by all the LEDs.
It will allow only one player light to be active after the first button press.

Of course, that may not meet the TS's part type limitation.

 

Here is a circuit using CMOS logic chips, based on D type flip flops.

That's more info than is supposed to be given in the Homework Help forum.
That's why I didn't post the circuit.

 

That's more info than is supposed to be given in the Homework Help forum.
That's why I didn't post the circuit.

Oops, it’s been so long that I forgot it was in homework help. I’ve deleted it.

 

Stick this in your filing cabinet also!
http://www.talkingelectronics.com/projects/50 - 555 Circuits/50 - 555 Circuits.html
Max.

thanks?