The tree diagram relates the weather forecast and school closings. Find the probability (as a percent) that the school is closed tomorrow if there is a

Question

90
90% chance for heavy snow.

H - heavy snowfall L - light snowfall C - closed O - open

Answer 1

H - 90% chance of heavy snowfall
L - 10% chance of light snowfall

If there is a 90% chance of heavy snowfall, then:
P(C|H) = Probability of school being closed given heavy snowfall = 100%
P(O|H) = Probability of school being open given heavy snowfall = 0%

So, the probability that the school is closed tomorrow if there is a 90% chance for heavy snow is 100%.