Y IS THE ANS BLACKENED???
IS THIS THE ANS : 12(3^(n-2)-2^(n-1)+1) ???
n balls are picked, one by one from four urns each containing n identical balls of green, red, white and blue colours. The number of ways, when no two consecutive pickings are from same urn and balls of all the colours are picked,
i know that too
i want the nice big subjective method for this one( thats why dint take the trouble to post the options)