Suppose Simaxiangru is in Dalian and Zhuowenjun is in Yantai. Simaxiangru has a date with Zhuowenjun at Yantai. There are four ways to arrive Yantai: walking, carriage, riding horse and taking boat . The probability of travelling by these four ways for is 0.3 , 0.2 , 0.1 , 0.4. The probability of failling the date by these four ways is 0.3, 0.2, 0.1, 0.05 respectively for Simaxiangru . Solve: (1) What is the probability of failling the date for Simaxiangru? (2) What is the probability of arrive Yantai by horse in case of failling the date for Simaxiangru? 假设司马相如在大连,在烟台;司马相如想到烟台与约定相会。司马相如有步行,坐马车,骑马,坐船四种方式到达烟台。且他采用这几种交通方式出行的概率为0.3 , 0.2 ,0.1 , 0.4;同时他采用这几种交通爽约的概率分别为0.3, 0.2, 0.1, 0.05.试问: (1) 司马相如爽约的概率多大? (2)如果发现司马相如爽约了,司马相如骑马出行的概率多大?