Put the equations in for r and c
p(c)=10x-(4x+15)
put the negaive in
10x-4x-15
6x-15
Answer is C
Answer:
It will take him 7 ½ days.
Step-by-step explanation:
He goes up 2 ½ but falls back down ½ so you take the two and do 15/2 and get 7.5 which is 7 ½ days.
There would be a 10% chance that they would have the same birthday