SOLUTION
Given the question in the image, the following are the solution steps to answer the question.
STEP 1: Write the formula for probability

STEP 2: Find the probability that a class attendee is a non member of the gym and is attending a barre class
Using the table, the number of required outcomes is:
Therefore,

STEP 3: Find the probability that a class attendee is a member of the gym and is attending a yoga class
Using the table, the number of required outcomes is:
Therefore,

STEP 4: Find the probability that a class attendee is a non member of the gym and is attending a barre class or is a member of the gym and is attending a yoga class.
Using the addition law of probability, the probability either will be the sum of the two derived probabilities.

Hence, the probability that a class attendee is a non member of the gym and is attending a barre class or is a member of the gym and is attending a yoga class is 491/2065