Consider the following premises. For all x_3, x_3 will not sleep. There is at least one x_3 for which if x_3 works, then x_3 is making tea. For all x_3, x_3 will sleep if and only if x_3 will make tea. Can we infer the following from them? There is at least one x_3 for which x_3 will not work.
 From the fact that for all x_3, x_3 will sleep if and only if x_3 will make tea, and that for all x_3, x_3 will not sleep we can infer that for all x_3, x_3 will not make tea. Finally, from the fact that there is at least one x_3 for which if x_3 works, then x_3 is making tea, and that for all x_3, x_3 will not make tea we can infer that there is at least one x_3 for which x_3 will not work. Therefore, the answer is yes.