In Exercise 11.2.13, are the events that a randomly chosen person uses Twitter and a randomly chosen person uses Instagram complements of each other? What would have to be true about Twitter and Instagram users for these two events to be complements of each other?

Data from Exercise 11.2.13

As estimated by the Pew Research in 2016, the probability a randomly chosen American adult uses Instagram is 0.28, the probability a randomly chosen American adult uses Twitter is 0.21, and the probability a randomly chosen American adult uses Instagram and Twitter is 0.14.