If a, b and c are non-zero, a + (1/b) = 1 and b + (1/c) = 1, then the value of abc is

∵ a + (1/b) = 1
ab + 1 = b ......(i)
Also, b + (1/c) = 1
⇒ b = 1 - (1/c) ....(ii)
From Eqs. (i) and (ii), we get
ab + 1 = 1 - (1/c)
⇒ ab = -1/c
⇒ abc = -1