A new flag is to be designed with 6 vertical strip using some or all of the colour yellow,green,blue and red . Then the no. Of ways this can be done such that no two adjacent strips have the same colour is

The ans. Is 972 ways. In general for a flag of n colored strips number of ways = 4×3^(n-1). The method is long or can`t be typed...and i think there is no option for sending image files in answers. Just try to alalyse the question by first taking only 1 stip in a flag , then 2strips and so on....