The answer is A. (1, 4), because when the values are substituted in to the equations, you get 1 = 4 - 3 and 1 + 12 = 13, which are both correct. I hope this helps!
Answer: 
Step-by-step explanation:
Binomial probability formula :-
, where P(x) is the probability of getting success in x trials, n is the total number of trials and p is the probability of getting success in each trial.
We assume that the total number of days in a particular year are 365.
Then , the probability for each employee to have birthday on a certain day :

Given : The number of employee in the company = n
Then, the probability there is at least one day in a year when nobody has a birthday is given by :-

Hence, the probability there is at least one day in a year when nobody has a birthday =
Your question seems incomplete
is there an image supposed to be attached to it
Here is the answer
I did it with steps
3a+2(4a-1)=9
3a+8a-2=9
11a=11
a=1