342,198,75If the digit 2 in the number above is replaced by

In the question,there is 342,198,75 or 342,198.75?
（题目是34219875还是342198.75,第二个标点有疑问阿）
If the digit 2 in the number above is replaced by the digit 6,by how much will the number increase?
It increases 400000（or 4000.00）
In how many different ways can three men and three women be arranger in a line so that the men and the women alternate?
P3*P3*2=72