Find the z-score boundaries that separate a normal distribution as described in each of the following

Find the rate at which the water is now flowing from the tap give your answer cubic centimetres per second

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

Can someone me and explain..will award brainlest!