Solution:
Let the plane meet the edges DA, DB and DC at points P, Q and R, respectively. Set
DADP=x,DBDQ=y, and DCDR=z
Let M be the midpoint of AB and L=DM∩PQ. It follows from the condition of the

problem that DMDL=31. Therefore
SDAMSDLP=DA⋅DMDP⋅DL=3x;SDMBSDLQ=DM⋅DBDL⋅DQ=3y
Since SDAM=SDMB=21SDAB we conclude that
2xy=2DA⋅DBDP⋅DQ=21SDABSDPQ=SDAMSDPL+SDMBSDLQ=3x+y
i.e. x1+y1=6. Analogously y1+z1=8 and z1+x1=10. Solving this system we obtain x=41, y=21 and z=61. Thus
VDABCVDPQR=DA⋅DB⋅DCDP⋅DQ⋅DR=xyz=481
and therefore the desired ratio equals 1:47.