this is on probability for stat.
Any help is appreciated :)

Answer:
The answer is 97%
Step-by-step explanation:
If you consider the attached tree diagram, there are two possibilities (In green) that you are looking for:
The probability of scenario 1 is 70% and the probability of scenario 2 is 30% * 90% = 27%.
Since we can have either possibility, we add the two together to get 70% + 27% = 97%.