A petrol attendant recorded the number of vehicles that bought petrol from him for -3 hours and recorded 12 cars and 27 buses. What is the probability that the next vehicle will be a bus?
-
A.
(frac{4}{39}) -
B.
(frac{4}{13}) -
C.
(frac{5}{13}) -
D.
(frac{6}{13}) -
E.
(frac{9}{13})