Measurement of ratio of 3-jet to 2-jet cross sections

Recent measurements on multijet production in ppbar collisions at sqrt{s} = 1.96 TeV are presented. We analyze the data set corresponding to an integrated luminosity of 0.7 fb$^{-1}$ taken with the D0 detector at the Fermilab Tevatron collider. The measured observable is the ratio of 3-jet to 2-jet inclusive jet cross-sections. This ratio is measured as a function of transverse jet momentum.