Question

the number of n-digit numbers, no two consecutive digits being the same, is
a. n!
b. 9!
c. 9^n
d. n^9

Answer 1

Answer:  The answer is $(c). 9^n.$

Step-by-step explanation:  We are to find the number of n-digit numbers where no two consecutive digits are same.

Number of 1 digit numbers = 9,

Number of 2-digit numbers, with no two consecutive digits same = 81 = 9²,

Number of 3-digit numbers, with no two consecutive digits same = 273, etc.

Therefore, number of n-digit numbers, with no two consecutive digits same is given by

$9^n.$

Thus, (c) is the correct option.

Answer 2

Answer:

answer is c option ie 9^ n