HOMEWORK 4 Exercise 1. Using the Mayer-Vietoris exact sequence compute the homology groups of the sphere with two handles. Exercise 2. Consider a surface which consists of the disk to which is attached the Moebius band in such a way that we stick the boundary of the Moebius band (homeomorhic to S1 ) to the boundary of the disk. Using the Mayer-Vietoris exact sequence compute the homology of this surface. (In fact, this is the projective plane.) 1