Question 385048

We can paint first house by any one of colors(red, blue, green)...

so, no. of ways to paint first house = 3

now, no. of ways to paint second house = 2  (except the color of first house)

similarly, no. of ways to paint third house = 2 (except the color of second house)

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similarly,no. of ways to paint seventh house = 2 (except the color of sixth house)


total no. of ways = 3* 2^6

= 3 *64 

= 192