Premise: "A cowboy wearing a brown shirt that says us army holding a horses lead."
Hypothesis: "The cowboy is getting ready to ride the brown horse."
Do we know that the hypothesis entailed by the premise?
Let's solve step-by-step:
A cowboy wearing a brown shirt that says US Army holding a horses lead does not imply that he is getting ready to ride the brown horse. The answer is it is not possible to tell.