What is the probability that one randomly selected physician is a man or is 35-44 years old

Based on this table, the probability that the physician is a man is 78%
Now, if the physician is a man and 35-44 years old, he’s already included in that 78%, so we only need to now consider the possibility that they physician is female and 35-44 years old: 8%.

So the total probability is 78% (male) + 8% (female and 35-44) = 80%

This can also be found by adding up all the individual probabilities in your table: