Based on data corresponding to an integrated luminosity of 0.37 fb(-1) collected by the LHCb experiment in 2011, the following ratios of branching fractions are measured: B(B-0 ->pi(+)pi(-))/B(B-0 -> K+pi(-))=0.262 +/- 0.009 +/- 0.017, (f(s)/f(d)).B(B-s(0)-> K+K-)/B(B-0 -> K+pi(-))=0.316 +/- 0.009 +/- 0.019, (f(s)/f(d)).B(B-s(0)->pi K-+(-))/B(B-0 -> K+pi(-))=0.074 +/- 0.006 +/- 0.006, (f(d)/f(s)).B(B-0 -> K+K-)/B(B-s(0)-> K+K-)=0.018(-0.007)(+0.008)+/- 0.009, (f(s)/f(d)).B(B-s(0)->pi(+)pi(-))/B(B-0 ->pi(+)pi(-))=0.050(-0.009)(+0.011)+/- 0.004, B(Lambda(0)(b)-> p pi(-))/B(Lambda(0)(b)-> pK(-))=0.86 +/- 0.08 +/- 0.05, where the first uncertainties are statistical and the second systematic. Using the current world average of B(B-0 -> K+pi(-)) and the ratio of the strange to light neutral B meson production f(s)/f(d) measured by LHCb, we obtain: B(B-0 ->pi(+)pi(-))=(5.08 +/- 0.17 +/- 0.37)x10(-6), B(B-s(0)-> K+K-)=(23.0 +/- 0.7 +/- 2.3)x10(-6), B(B-s(0)->pi K-+(-))=(5.4 +/- 0.4 +/- 0.6)x10(-6), B(B-0 -> K+K-)=(0.11(-0.04)(+0.05)+/- 0.06)x10(-6), B(B-s(0)->pi(+)pi(-))=(0.95(-0.17)(+0.21)+/- 0.13)x10(-6). The measurements of B(B-s(0)-> K+K-), B(B-s(0)->pi K-+(-)) and B(B-0 -> K+K-) are the most precise to date. The decay mode B-s(0)->pi(+)pi(-) is observed for the first time with a significance of more than 5 sigma.