Conditional probability -plz help

1. Jean travels by bus or taxi. The probability that she takes bus on one day and she goes by taxi the next day is 0.4, the probability that she takes taxi on one day and she goes by bus the next day is 0.7. Given Jean takes bus on Monday, find the probability that she takes a taxi on Wednesday?

2. Two coins are flipped. One is fair with head on one side and tail on other. The second coin is tricky one - it has 2 tails on both sides. She picks one at random and flips it.

(a) Probability it lands heads up?

(b)it lands tails up, probability she picked up fair coin?

Any help or hint much appreciated

Thanks in advance

Dee