A simple ques. from Student to his teacher

Sir - "Birbal Kaun Tha?"

Student - "Pata Nahi Sir"

Sir - "Padhaai Par Dhyaan Do To Na Pata Chale"

Student - "Pramod, Vicky, Gaurav Kaun Hai?"

Sir - "Mujhe Kya Pata"

Student - "Beti Par Dhyaan Do To Na Pata Chale"...