A) \[{{8}^{n}}\]
B) \[{{9}^{n}}\]
C) \[9\cdot {{10}^{n-1}}\]
D) None of these
Correct Answer: C
Solution :
\[\underset{{{x}_{1}}}{\mathop{}}\,\underset{{{x}_{2}}}{\mathop{}}\,...\underset{{{x}_{n}}}{\mathop{}}\,\] The digit \[{{x}_{1}}\] can be selected in \[9\] ways as \[0\] cannot be selected. The digit \[{{x}_{2}}\] can be selected in \[9\] ways as \[0\] can be selected but digit in position\[x\], cannot be selected. Similarly, all the remaining digits can also be selected in \[9\] ways each. Thus, total number of such numbers\[={{9}^{n}}\]
You need to login to perform this action.
You will be redirected in
3 sec
