Quarks carry spin-1/2. Three quarks bind together to make a baryon (such as a proton or neutron); two quarks (or more precisely a quark and an antiquark) bind together to make a meson (such as the pion or kaon). Assume that the quarks are in the ground state (so that the orbital angular momentum is zero). What spin quantum numbers s are possible for (a) baryons, (b) mesons?