Final answer:
To find the probability of students who like EXO only, subtract the number of students who like both Justi Bieber and EXO from the total number of students who like EXO. Divide the number of students who like only EXO by the total number of students for the probability.
Step-by-step explanation:
To find the probability of students who like EXO only, we need to subtract the number of students who like both Justi Bieber and EXO from the total number of students who like EXO.
Given that 17 students like Justin Bieber and 18 students like EXO, let's assume that there are x students who like both. So, the number of students who like only EXO would be 18 - x.
The probability can be calculated by dividing the number of students who like only EXO by the total number of students:
Probability = (18 - x) / (17 + 18 - x)