Each weekday Alan drives to work. On his journey, he goes over a level crossing. Sometimes he has to wait at the level crossing for a train to pass.
• W is the event that Alan has to wait at the level crossing.
• L is the event that Alan is late for work.
You are given that P(L│W) = 0.4. P(W) = 0.07. P(L or W) = 0.08.
(i) Calculate P(L and W).
I have calculated this as 0.4 x 0.07 = 0.028 (ii) Draw a Venn diagram, showing the events L and W. Fill in the probability corresponding to each of the
four regions of your diagram. [3]
This is the bit I am confused on. The picture I have attached below is what the markscheme says.
I don't understand how P(L) = 0.01. This is because
P(L or W) = P(L) + P(W) - P(L and W)
Therefore
0.08 = P(L) + 0.07 - 0.028.
Therefore, I have worked out the probability of L to be 0.038.
Any help would be really really appreciated.
Thank you