MathDB
Turkish NMO First Round - 2000 P-30 (Number Theory)

Source:

July 8, 2012

Problem Statement

How many ordered integer pairs (x,y)(x,y) (0x,y<310\leq x,y < 31) are there satisfying (x218)2y2(mod31)(x^2-18)^2\equiv y^2 (\mod 31)?
<spanclass=latexbold>(A)</span> 59<spanclass=latexbold>(B)</span> 60<spanclass=latexbold>(C)</span> 61<spanclass=latexbold>(D)</span> 62<spanclass=latexbold>(E)</span> None <span class='latex-bold'>(A)</span>\ 59 \qquad<span class='latex-bold'>(B)</span>\ 60 \qquad<span class='latex-bold'>(C)</span>\ 61 \qquad<span class='latex-bold'>(D)</span>\ 62 \qquad<span class='latex-bold'>(E)</span>\ \text{None}