(a+b)/ab=6 a+b=6ab (a+b)c=6abc ①
(b+c)/bc=8 b+c=8bc (b+c)*a=8abc ②
(a+c)/ac=10 a+c=10ac (a+c)*b=10abc ③
①+②+③,得
2（ab+bc+ac)=24abc
(ab+bc+ac)/abc=12