  We prove several results of the following type: any $d$ measures in $\mathbb
R^d$ can be partitioned simultaneously into $k$ equal parts by a convex
partition (this particular result is proved independently by Pablo Sober\'on).
Another example is: Any convex body in the plane can be partitioned into $q$
parts of equal areas and perimeters provided $q$ is a prime power.
  The above results give a partial answer to several questions posed by A.
Kaneko, M. Kano, R. Nandakumar, N. Ramana Rao, and I. B\'{a}r\'{a}ny. The
proofs in this paper are inspired by the generalization of the Borsuk--Ulam
theorem by M. Gromov and Y. Memarian.
  The main tolopogical tool in proving these facts is the lemma about the
cohomology of configuration spaces originated in the work of V.A. Vasil'ev.
  A newer version of this paper, merged with the similar paper of A. Hubard and
B. Aronov is {arXiv:1306.2741}.
