2. What is the value of $(0.5)^{3}+3 \times(0.5)^{2} \times(-1.5)+3 \times(0.5) \times(-1.5)^{2}+(-1.5)^{3}$ ?
(a) 1 ;
(b) -1 ;
(c) 0 ;
(d) 2 ;
(e) -2 .
2 Ans: (b).
Let $f(a, b)=(a+b)^{3}=a^{3}+3 a^{2} b+3 b^{2}+b^{3}$. Then $f(0.5,-1.5)=(0.5-1)^{3}=-1$.