Question

en is travelling home to Birmingham on the M1 and M42. Both motorways have road works. He has a fifty-fifty chance of getting delayed on the M42 and a 75% chance of being delayed on the M1. What are the chances that he will not be delayed on his journey? 1 in 4 3 in 8 1 in 8 1 in 2

Answer 1

P(delay on M₁) = 0.75.
P(NOT delayed on M₁) = 1 - 0.75 = 0.25

P(delay on M₄₂) = 0.5
P(NOT delayed on M₄₂) = 1 - 0.5 =0.5

P(NOT delayed on M₁ AND Not delayed on M₄₂) = (0.25).(0.5) =(1/4).(1/2)

P(NOT delayed on M₁ AND Not delayed on M₄₂) = 1/8 (one in 8)