. There are 6 choices for the first digit, 5 choices for the second digit, 4 for the third, etc.2. Find the number six-digit numbers that can be formed using the digits from the number 112233. If these numbers are arranged in ascending order, find the 30th number and the median.
There are 6 choices for the first person to put into the first group, 5 choices for the second person to put into the first group, 4 choices for the first person to put into the second group etc. The difference between this and problem two is that this problem say "three groups"- it does NOT specify a 'first group', 'second group', 'third group'. So you have to divide by the number of ways of "ordering" the three groups- there are three ways to choose a "first group", two ways to choose a "second group"- and then of course, there the last group is fixed.3. How many ways can six people be divided into three groups of two people each?
Please show me the working for these kind of questions, thank you very much.
PS: I always wonder, for question 2, did it really related to probability?