Question 338940
Each of six adjacent squares in a strip is to be filled with anyone of ten possible colors. How many ways are there of coloring the strip so that no two adjacent squares have the same color? 
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1st square: 10 ways
2nd square: 9 ways
3rd square: 9 ways
4th square: 9 ways
5th square: 9 ways
6th square: 9 ways
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Total # of ways: 10*9^5 = 590490 ways
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Cheers,
Stan H.