已知六个数a、b、c、d、e、f满足a/b=1/2,b/c=-1/3,c/d=1/4,d/e=-1/5,e/f=1/6,则f/a=

Question

已知六个数a、b、c、d、e、f满足a/b=1/2,b/c=-1/3,c/d=1/4,d/e=-1/5,e/f=1/6,则f/a=

Answer 1

720
设a=1 b=2 c=-6 d=-24 e=120 f=720