I suppose a DJ wants to select 4 different songs, then there are: 12*11*10*9 = 11880 ways to choose them.
If the order of the songs he plays doesn't matter, there are: ways to choose them.
Answer:
The answer is NOT 495 WAYS (for when choosing 5) !!!! The CORRECT answer is 792!!!!!
>>>495 may be the answer "when choosing (four)"
UPDATE: This is the answer for when "choosing FIVE" not FOUR.
A. -205.7 kJ
Step-by-step explanation:
The overall enthalpy of reaction be calculated when the intermediate steps are present
formed in a multi-step process.
C=2
-8(17-12)= -8(5)= -40
then
-2(8-(-2))= -2(10) = -20
so then
-40/-20
=-2
21