How many 4 digits number contain the number 2.  Pick
A) 3170  B) 3172  C) 3174  D) 3168  E) 3167
total no. of 4 digit nos are 9000(btwn 1000 and 9999).   consider the case where the nos contain no 2 in it.   so units place can be filled in 9 ways(0,1,3,4,5,6,7,8,9)   smlry,tenths place in 9 ways   hunderedths place in 9 ways   thousands place can be filled in 8 ways only(because 0 cannot come)   so total nos are   (9000-(8*9*9*9))= 
<gadget id="calculator">  (9000-(8*9*9*9))</gadget>
<output>3_168</output>
3168   ANSWER:3168
<result>D</result>
How many 4 digits number contain the number 2.