Answer:
0.40
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
Desired outcomes:
Exit A or exit B, so 2 desired outcomes.
This means that 
Total outcomes:
Any of the 5 exits, so 
Probability:

0.0166 because it’s bigger than all other numbers
7n + 3 = 3n + 27
7n -3n =27-3
4n =24
n= 6.
Can you please add a picture of the problem or type all the measurements and information?