Help needed on 7-Segment Display.

I am given task:

Design an octal-to-7-segment common cathode decoder for digits 0 to 5 only using the least possible number of basic gates (i.e. an optimum design). The 7-segment will only need to display from octal digits 0 to 5, ignore other numbers Your solutions must show all the design steps taken, i.e. a description of the task, requirements definition, design approaches such as truth-table(s), simplification using K-maps or Boolean theorems, and the implementation (circuit diagrams) using standard logic symbols.

I have come out with the truth table. But I'm clueless about the basic gates needed, simplification using K-maps or Boolean theorem,

3 switches name A, B, C.
so when the switches are:
* A=off/0 B=off/0 C=off/0 *, the display will be 0
* A=off/0 B=off/0 C=on/1 *, the display will be 1
* A=off/0 B=on/1 C=off/0 *, the display will be 2
* A=off/0 B=on/1 C=on/1 *, the display will be 3
* A=on/1 B=off/0 C=off/0 *, the display will be 4
* A=on/1 B=off/0 C=on/1 *, the display will be 5

Would REALLY REALLY appreciate if anyone can help.

So they haven't taught you anything about K-maps or the Boolean theorem? If you are clueless about them I suggest you do some reading.

You need to expand your truth table to show which display segments need to be lit for each of the numbers.

Hi, thanks for the reply.

They have taught me about K-map and Boolean theorem. But i do not have any idea of applying it to the truth table results. For the truth table i am only required to diaplay 0-5 on the 7segment display.

I am using NI multisim to design the circuit. I tried but i can't get the correct out come

https://www.flickr.com/photos/64214999@N05/5847860619/sizes/l/in/photostream/

Thank you