Por que se a incrementado el uso del oxigeno medicinal en la epoca de pandemia​

In order to be invited to tutoring or extension activities a students performance 20 point higher or lower than average for the

Math i have no idea how to do a and b

At a pizza shop 70% of the customers order a pizza 25% of the customers order a salad and 15% of the customers order both a pizza and a salad if s customer is chosen at random what is the probability that he or she orders either a pizza or a salad