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?
\(\frac{4}{39}\)
\(\frac{4}{13}\)
\(\frac{5}{13}\)
\(\frac{6}{13}\)
\(\frac{9}{13}\)
Correct answer is E
No explanation has been provided for this answer.