Sue travels by bus or walks when she visits the shops.
Probability( catch the bus to the shop ), P(A) = 0.4
Probability( catch the bus from the shop ), P(B) = 0.7
Both A and B are independent events.
P(A∩B) = 0.4×0.7
Probability Sue walks one way = 1 - P(A∩B)
= 1 - 0.28
Hence, the probability that Sue walks at one way is 0.72
That is what I did in the box and got the correct answer. Hope you have a good day!
last time i did this i got 1.4