imho the Yogis and Sidhs that confronted the "Balak" (child) Nanak were all puffed up with what they had seemingly achieved via their secluded way of life..they thought they were reaching/or had already reached the other shore of this world of maya..and were wondering what a mere child that stood before them could teach them ?? Thus the questions.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/sidh-gosht/5309-sidh-gosht-gurumukhi-script-english-transliteration.html
Guru Ji gave the answers....that it is "HE" who is asking...and its "HE" who is answering....and to know all the answers one has to know the "HE"..by being as near to HIM as we possibly can..and one way of getting near Him is by the life of a householder, carrying out ones social and moral responsibilities and NOT by renunciation and abdication of ones responsibilities to family and society. No amount of solitary life, consuming only roots and veges fruits etc can achieve nearness to HIM..in fact the Haumai created by such acts takes one farther away ( as the Yogis demonstrated via various acts of sidhis and ridhis that failed to impress the child Nanak....the condescending use of the word BALAK (child) already shows how highly the oldies regarded themselves as compared to Nanak Ji...in reality they were not really seeking any answers..rather they were TESTING Nanak and that too in a most condescending way.