Could someone please explain I keep getting the wrong answer

Iwill make brain if you me correctly fill this out needs due today pls and send it back to me (click the link and you will get it)

How many different three-digit numbers can be formed using the digits 1 comma 2 comma 9 comma 6 comma 4 comma 3 comma and 8 without repetition? for example, 664 is not allowed.

There were 25 students who answered to a survey about sports. four-fifths of them like football. how many students like football?