Let c and d be the number of cds and dvds respectively.
c+d=12
c=12-d
The we are told that:
2c+3d=31, using c found above in this equation gives you:
2(12-d)+3d=31
24-2d+3d=31
24+d=31
d=7
So Phillip bought 7 dvds.
check...
3*7+2(12-7)=31
21+2(5)=31
21+10=31
31=31
Answer:
from what I remember ide say A
It represents that she tutored for 0 hours, and earned $0.
Answer:
P(A or B) = 25%
Step-by-step explanation:
P(A and B) = 30%
P(A) = 40%
P(B) = 15%
Apply given formula:
P(A or B) = P(A) + P(B) - P(AB)
= 40%+15+-30%
= 25%
