The probability tree diagram shows the probabilities that Bismah will be late for work on two days next week - Edexcel - GCSE Maths - Question 12 - 2019 - Paper 3

The probability that Bismah is not late on Monday is 0.93, and the probability of being late on Tuesday is 0.02. Therefore, the combined probability is:

$P(NotLate_{Mon} ext{ and } Late_{Tue}) = 0.93 imes 0.02 = 0.0186$

To find the total probability that Bismah is late on exactly one of the two days, we add the probabilities from the two previous calculations:

$P(Late ext{ exactly one day}) = P(Late_{Mon} ext{ and } NotLate_{Tue}) + P(NotLate_{Mon} ext{ and } Late_{Tue})$

This results in:

$P(Late ext{ exactly one day}) = 0.0686 + 0.0186 = 0.0872$