(a) A perfectly balanced coin is tossed 3 times and tail appears on all 3 tosses. Calculate probability of a tail on the 4th trial.(b) An economist predicts a 60% chance of recession in country A and a 25% chance of recession in country B. There is 64% chance of a recession in country A given that country B is in recession. What is the probability that country B in recession given that country A in recession?