Measurement of the ratios of branching fractions B (B(s)(0)-> D(s)(-) pi(+) pi(+) pi(-))/B(B(0) -> D(-) pi(+) pi(+) pi(-)) and B(B(s)(0) -> D(s)(-) pi(+))/B(B(0)-> D(-) pi(+))

Using 355 pb(-1) of data collected by the CDF II detector in p (p) over bar at collisions at root s = 1.96 TeV at the Fermilab Tevatron, we study the fully reconstructed hadronic decays B((s))(0) -> D((s))(-)pi(+) and B((s))(0) -> D((s))(-) pi(+)pi(+)pi(-). We present the first measurement of the ratio of branching fractions B(B(s)(0) -> D(s)(-) pi(+)pi(+)pi(-))/B(B(0) -> D(s)(-) pi(+)pi(+)pi(-)) = 1.05 +/- 0.10(stat) +/- 0.22(syst). We also update our measurement of B(B(s)(0) -> D(s)(-)pi(+))/B(B(0) -> D(-)pi(+)) to 1.13 +/- 0.08(stat) +/- 0.23(syst), improving the statistical uncertainty by more than a factor of 2. We find B(B(s)(0) -> D(s)(-)pi(+)) = [3.8 +/- 0.3(stat) +/- 1.3(syst)] x 10(-3) and B(B(s)(0) -> D(s)(-) pi(+)pi(+)pi(-)) = [8.4 +/- 0.8 (stat) +/- 3.2(syst)] x 10(-3).