We are asked to find the probability that the student sold 11-15 T-shirts or less than 6 T-shirts.
The total number of club members = 2 + 14 + 12 + 3 + 6 + 1 = 38
Probability of 11-15 T-shirts:
From the table, 3 club members bought 11 - 15 T-shirts.
So the probability is 3/38
Probability of less than 6 T-shirts:
Less than 6 T-shirts means 1 - 5 plus 0 T-shirts.
Form the table, 14 club members bought 1 - 5 T-shirts and 2 club members bought 0 T-shirts.
Total club member who bought 1 - 5 and 0 T-shirts = 14 + 2 = 16
So the probability is 16/38
Now we have to add them together to find the probability that the student sold 11-15 T-shirts or less than 6 T-shirts.
(or means to add)
So the probability is 3/38 + 16/38 = 19/38 = 0.5000
Therefore, the correct answer is option c.
