Answer:
10
Step-by-step explanation:
n is the number of selections and k the number selected, that is
n = 5 and k = 2
note that n! = n(n - 1)(n - 2) ..... × 3 × 2 × 1, thus

= 
= 
= 
= 10
Answer:
x
Step-by-step explanation:
Answer:
POSITIVE
Step-by-step explanation:
POSITIVE cuz it goes up
Answer:
30 minutes
Step-by-step explanation:
She plays 1/2 of a song in 1/4 of a minute so that would be 15 minutes because if you divide 60 by 4 you would get 15. You would multiply 15 by 2 because if she plays a full song you multiply 1/2 by 2 to get a whole. So she will need 30 minutes to play a full song