How many 6 digit positive integers exist such that no two consecutive digits are the same?	Choose the correct choice
A) 10*9*8*7*6*5
B) 9*8*7*6*5*4
C) 9*9*8*7*6*5
D) 9*9*8^4
E) 9^6
no two consecutive integers are same, so the digit is in the form of XY XY XY   so leftmost digit can be any digit but 0. we can choose in 9 ways. next digit can be chosen in 9 ways, remaining each digit can be chosen in 9 ways.   total digits are 9∗9∗9∗9∗9∗9=9^6   Ans. 9^6
<result>E</result>
How many 6 digit positive integers exist such that no two consecutive digits are the same?