Why does the conductor refer to Valli as ‘madam’?
The conductor refers to Valli as ‘madam’ because he is a jolly sort who is fond of joking. He is amused by her grown-up behavior, as she confidently pays her own thirty paise fare and insists on traveling to the city all alone without anyone's help.
By addressing a young girl as 'madam', he playfully teases her for acting like an independent adult. His lighthearted teasing highlights the contrast between her actual age and her mature demeanor, which makes him and the other passengers laugh.
Explanation
The textbook explicitly mentions that the conductor was a 'jolly sort, fond of joking.' When Valli shows independence by paying her fare and traveling alone, he calls her 'madam' to playfully mock her serious, grown-up attitude. He even asks an elderly man, 'Do you think a mere girl could pay her own fare and travel to the city all alone?', showing that his use of 'madam' is a humorous acknowledgment of her self-reliance.