the answer is D because it is the only answer that was clearly defined in the question.
Hope this helps! if it didn't, let me know in the comments! have a great day!
The first selection can be any one of the 8.
For each one ...
The second selection can be any one of the remaining 7.
For each one ...
The third selection can be any one of the remaining 6.
For each one ...
The fourth selection can be any one of the remaining 5.
Total number of ways to select four = (8 x 7 x 6 x 5) = 1,680 ways
BUT ... There are not 1,680 different groups of 4 .
Each group of 4 can be selected in (4 x 3 x 2) = 24 different ways.
So, although there are 1,680 different ways to select 4 singers,
there are only
(1,680 / 24) = 70 different groups of 4
that you can end up with.
There is 7,000 female students, and 5,000 male students. Because, if there was 2,000 more female students then male, you have to find out what two numbers add up to 12,000. (Tip, to make it easier, take away the thousands, like 7+5)
-4w+y+3 is the correct answer
