8. Suppose that only one of the following pairs $(x, y)$ yields the positive integer $\sqrt{x^{2}+y^{2}}$. Then
(A) $x=25530, y=29464$;
(B) $x=37615, y=26855$ :
(C) $x=15123, y=32477$;
(D) $x=28326, y=28614$;
(E) $x=22536, y=27462$.
8. Ans: (A)
Since $x^{2}+y^{2}$ is a perfect square, its last digit must be $0,1,4,5,6$, or 9 . Hence (C) and (D) are not suitable. For (B) and (e), the last two digits are 50 and 60 resp. However, if a number ends with 0 , its square must end with two 0 's. Thus the ans is (A) where $\sqrt{x^{2}+y^{2}}$ turns out to be 38986 .