Problem: XY Plumbing
X, Y, and Z agree to carry on business in partnership under the firm name XY Plumbing. Y, in the course of partnership business, carelessly injures T. T intends to take legal action against the partnership for the injury, but is unaware that Z is a partner, since his name is not included in the partnership name.
Is Z liable if T sues only X and Y?
In your response, consider course materials, define relevant legal concepts, and provide reasons for your opinion.