The question is:
Forty percent of the people in a town watch both basketball games and
hockey games regularly. 55 percent watch basketball games and 63
percent watch hockey games regularly. If one person is chosen
randomly, what is the probability that this person watches neither
basketball games nor hockey games regularly?
I've tried to construct a probability tree (which did not bear any results). I also tried to do 1 – (probability that they watch hockey, basketball, or both) however it's the final part of that equation which I seem to have trouble with. How do I calculate the probability that a randomly chosen person watches hockey, basketball, or both?
Best Answer
If forty percent of the people watch both sports, then 15 percent watch only basketball (55-40) and 23 percent watch only hockey (63-40). Therefore we have 100-40-15-23=22 percent of people watching neither one of the sports. So if we choose a random person the probability that he/she watches neither one of the sports is 22 percent.