Kanpur: A would-be-groom fumbling at a simple maths query cost his marriage as the girl refused to marry him and the wedding had to be called off.

Lovely (21), who is a class XII-pass, asked Rambaran (23) "how much is 15 added to six", ahead of the final ceremony on March 10, at Karerampur village in Rasulabad area of Kanpur Dehat, police said today.