6 When Sunil travels from his home in England to visit his relatives in India, his journey is in four stages. The times, in hours, for the stages have independent normal distributions as follows.
Bus from home to the airport: \(\quad \mathrm { N } ( 3.75,1.45 )\)
Waiting in the airport: \(\quad \mathrm { N } ( 3.1,0.785 )\)
Flight from England to India: \(\quad \mathrm { N } ( 11,1.3 )\)
Car in India to relatives: \(\quad \mathrm { N } ( 3.2,0.81 )\)
- Find the probability that the flight time is shorter than the total time for the other three stages.
- Find the probability that, for 6 journeys to India, the mean time waiting in the airport is less than 4 hours.