how many 4 digits number contain the number 2 .
"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 can not come ) so total nos are ( 9000 - ( 8 * 9 * 9 * 9 ) ) = 3168 answer : d"
add(subtract(subtract(const_1000, const_10), multiply(multiply(const_10, multiply(4, 4)), multiply(const_4, const_2))), const_10)