Kanjus Baap

Teacher: Tumhare papa 500 rupees loan lete hain. 10% interest ke hisab se voh 1 saal baad loan vapis karte hain. Batao kitne paise vapis karenge?
Student: Kutch bhi nahi.
Teacher: Tum maths nahi jante.
Student: Me to maths janta hu, par aap mere papa ko nahi jante.