Unselective and reversible adsorption of ligands on DNA for a model of binding proposed by Zasedatelev, Gursky, and Volkenshtein is considered. In this model, the interaction between neighboring ligands located at the distance of i binding centers is characterized by the statistical weight a_i. Each ligand covers L binding centers. For this model, expressions for binding averages are represented in a new simple form. This representation is convenient for the calculation of the fraction of inter-ligand distances of i binding centers f_d(i) and the fraction of binding centers included in the distances of i binding centers f_bc(i) for various types of interaction between bound ligands. It is shown that, for non-cooperative binding, contact cooperativity and long-range cooperativity, the fraction of the zero inter-ligand distance f_d(0) is maximal at any relative concentration of bound ligands (r). Calculations demonstrate that, at low r, f_d(0) approximately r · a_o, and f_d(i) approximately r at 1 ≤ i < 0.3 · r^-1 for non-cooperative binding (a_i = 1 for all i) and contact inter-ligand interaction (a_o ≠ 1, a_i = 1 for i ≠ 0). The function f_d(i) decreases in this i interval, but the decrease is very slow. If i > 1/r-L, then f_d(i) rapidly decreases with i at any r for all types of inter-ligand interaction. At high ligand concentration (r is close to r_max = L^-1), f_d(0) is close to unity and f_d(i) rapidly decreases with i for any type of inter-ligand interaction. For strong contact cooperativity, f_d(0) is close to unity in a much lager r interval ((0.5-1) · r_max), and f_d(1) ? a_o^-1 at r ∼ 0.5 · r_max. In the case of long-range interaction between bound ligands, the dependence f_d(i) is more complex and has a maximum at i ∼ (1/r-L)^1/2 for anti-cooperative binding. f_bc(i) is maximal at i approximately 1/r-L for all types of binding except the contact cooperativity. A strong asymmetry in the influence of contact cooperativity and anticooperativity on the ligand distribution along DNA is demonstrated.