AMC 8 Daily Practice Round 11

Complete problem set with solutions and individual problem pages

Problem 11 Medium

Positive integer n satisfies the equation: 180x = n^2. What is the smallest value of x?

  • A.

    2

  • B.

    5

  • C.

    20

  • D.

    45

  • E.

    180

Answer:B

180=2\times 2\times 3\times 3\times 5={{2}^{2}}\times {{3}^{2}}\times 5, 180x={{n}^{2}}, which is a perfect number, then x=5.