A simple form for the total weak-decay width of hadrons containing a h
eavy quark is proposed. The case of B-meson decays is considered in de
tail. B-meson transitions into single hadronic states (D, D, etc.) an
d into multihadrons are analyzed in the unified HQET and Bjorken's DIS
-type approach with a realistic (but model-dependent) b-quark distribu
tion function. A relatively large (about 14%) contribution of the so-c
alled ''internal'' nonleptonic decays is found; approximately 8% of th
is contribution comes from baryon-pair production. This corresponds to
the experimental data and leads, at the same time, to a considerable
reduction of the semileptonic decay ratio-down to its experimental val
ue of about 10%. The general picture of the distributions for the bran
ching ratios of the major B-decay types is presented. The results appe
ar convincing even when they are obtained in the zeroth order of the 1
/N-c expansion and in the zeroth order of perturbative (or nonperturba
tive) QCD.