Let a,b and c be real numbers which satisfy the equations a+ 1/bc=1/5,b+1/ac=(-1)/15 and c+ 1/ab=1/3. The value of (c-b)/(c-a) is equal to

Let a,b and c be real numbers which satisfy the equations a+ 1/bc=1/5,b+1/ac=(-1)/15 and c+ 1/ab=1/3. The value of (c-b)/(c-a) is equal to

127