Please help(20 points)

How to solve it and what thw answer is

Hello i need some with trigonometric substitutions. [tex]\int\limits^a_b {x} \, dx[/tex]

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