How many pairs of $(x, y)$ can be chosen from the set $\left\{2,3,6,8,9\right\}$ such that $\frac{x}{y}+\frac{y}{x}=2, \text{where} x\ne y?$

How many terms are there in the following product?

$(a_l+a_2+a_3)(b_1+b_2+b_3+b_4)(c_1+c_2+c_3+c_4+c_5 )$

If $a+b+c=0$ , then which of the following are correct?

1. $a^3+b^3+c^3=3abc$
2. $a^2+b^2+c^2=-2(ab+be+Ca)$
3. $a^3+b^3+c^3=-3ab(a + b)$

Select the correct answer using the code given below.