CBSE — Mistake in CBSE XII Mathematics Question Paper (Foreign Set)

I appeared in CBSE, AISSCE 2012-13 Mathematics exams on 20th March 2013 here in Nepal. In the question paper there was a mistake in set 65/2/1 in Q26.
It was asked to prove the given equation was homogeneous but there might be an error while printing because the question was not homogeneous. Also there was no appropriate method for solving such an equation in our syllabus. The equation was X2(square) dy/dx - xy = 1+cos(y/x)
I therefore request you to take a prompt action towards it as every mark is precious to us.