The cluster-reduction method is used to solve the differential Faddeev equations for S = 1/2, T = 0 and S = 3/2, T = 0 spin-isospin states of the Λnp system in the s-wave approximation. The NN interaction is simulated on the basis of the MT I-III potential model, and the ΛN potential is set to V_ΛN = V_NN/2. This simple option makes it possible to reproduce faithfully the binding energy of the hypertriton ³_ΛH . The doublet and quadruplet Λd scattering lengths and the low-energy phase shifts are calculated. It is shown that the effective-range approximation is applicable to the cases of doublet and quadruplet scattering.