In a certain car company, only two different car types, which are electric and hybrid, are produced. 5 % of the electric cars and 25 % of the hybrid cars are over 1500 kg. Moreover, 30 % of total cars are electric cars. 

a) Find the probability that a randomly selected car is under 1500 kg (Total Probability). 

b) If a car is randomly selected and observed to be under 1500 kg, what is the probability that the car is hybrid? (Bayes Theorem)