Make it easy

I encountered a problem in the morning. It was interesting, but it had not been solved. I had to wait until the evening, and now I finally solved it. I have never moved my mind recently. I have been working mechanically and people are aging. Now I want to take it easy.
I will describe the general meaning of the question:

There are 40 people in a team, including 30 people on horseback riding, 16 people on wrestling, 24 people on boxing, 14 people on horseback riding and wrestling, and 24 people on wrestling and boxing, eight people who can ride horses and boxing, the question is how many people in this team will ride horses, wrestling, and boxing (that is, the trigger )?

You may know the answer, but you need to write down the reasoning process.