Step-by-step explanation:

15 - c = 6
15 - 6 = c
9 = c
c = 9
Answer:
The answer is 12
Step-by-step explanation:
P(A) means "Probability of Event A" The complement is shown by a little mark after the letter such as A' (or sometimes Ac or A): P(A') means "Probability of the complement of Event A" The two probabilities always add to 1.
Can you post this and provide a picture please so I can help you ?
Explanation:
Each of the 4 friends spent 15 dollars so all you need to do is multiply 4 by 15. 4x15=60