MathDB
Square root is an integer

Source: AMC 12 2006A, Problem 10

February 5, 2006
AMC

Problem Statement

For how many real values of x x is \sqrt {120 \minus{} \sqrt {x}} an integer? <spanclass=latexbold>(A)</span>3<spanclass=latexbold>(B)</span>6<spanclass=latexbold>(C)</span>9<spanclass=latexbold>(D)</span>10<spanclass=latexbold>(E)</span>11 <span class='latex-bold'>(A) </span> 3\qquad <span class='latex-bold'>(B) </span> 6\qquad <span class='latex-bold'>(C) </span> 9\qquad <span class='latex-bold'>(D) </span> 10\qquad <span class='latex-bold'>(E) </span> 11