Exercise Habits Survey Analysis

In a recent survey of 150 individuals regarding their exercise habits, the responses were categorized as follows:

• 30 individuals prefer cardio exercises,
• 50 individuals prefer strength training,
• 20 individuals enjoy yoga,
• The remaining individuals have a mix of preferences across different types of exercise.

If 15 individuals reported that they participate in both cardio and strength training, how many individuals prefer only one type of exercise?