Digit not contained by arithmetic mean of the nine distinct numbers in the given set {9,99,999,9999,99999,999999,9999999,99999999,999999999}

The arithmetic mean of the nine numbers in the given set {9,99,999,.......999999999} is a 9 digit number N, all whose digits are distinct.The number N does not contain the digit

The arithmetic mean of the nine number in the given set {9,99,999, ...... 999999999} is a 9 digit number N, all whose digits are distinct. The number N does not contain the digit

The arithmaeic mean of the nine numbers in the given set {9,99,999,…..999999999} is a 9 digit number N, all whose digits are distinct. Then which digit does not appear in number

Mr. A randomly picks 3 distinct numbers from the set {1, 2, 3, 4, 5, 6, 7, 8, 9} and arranges them in descending order to form a three digit number. Mr. B randomly picks 3 distinct numbers from the set {1, 2, 3, 4, 5, 6, 7, 8} and also arranges them in descending order to form a 3 digit number. Q. The probability that A and B has the same 3 digit number is :

Mr. A randomly picks 3 distinct numbers from the set {1, 2, 3, 4, 5, 6, 7, 8, 9} and arranges them in descending order to form a three digit number. Mr. B randomly picks 3 distinct numbers from the set {1, 2, 3, 4, 5, 6, 7, 8} and also arranges them in descending order to form a 3 digit number. Q. The probability that A and B has the same 3 digit number is :

The geometric mean of three positive numbers a, b, c is 3 and the geometric mean of another three positive numbers d, e, f is 4. Also, at least three elements in the set {a, b, c, d, e, f} are distinct. Which one of the following inequalities gives the best information about M, the arithmetic mean of the six numbers?

The number of integers n with 100 le n le 999 and containing at most two distinct digits is