Check all apply 2x+2-9=5

Answer! if you don’t mind, can you explain

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

Which of the following is the sum of 3 1/6 + 6 3/8?