How to generate random numbers in excel without duplicates

Ajeweler designing a pin has decided to use five stones chosen from diamonds, rubies, and emeralds. in how many ways can the stones be selected?

Wich technology can a website use to allow you to listen to a concert live over the internet?

Design a pos circuit that displays the letters a through j on a seven-segment indicator. the circuit has four inputs w, x, y, and z which represent the last 4 bits of the uppercase ascii code for the letter to be displayed. thus, if wxyz = 0001 then "a" will be displayed. (any answer with 22 or fewer gates and inverters, not counting any for the inputs, is acceptable)