You cannot know that there is a leak in the tubes they are just giving a description of the tubes.
This justifies what answer for what question? Q & A: 
user
Premise: "A shirtless man and another in a gray shirt are looking at large blue and yellow corrugated tubes going down into a blue rimmed hole."
Hypothesis: "The men looked at the tubes trying to figure out where the leak was."
Do we know that the hypothesis entailed by the premise?
it is not possible to tell
assistant