If x = y^2, and x and y are positive integers, which of the following numbers could be the value of x?  Pick one: A) 12,947 B) 13,872 C) 14,323 D) 15,568 E) 16,641
The square of an integer can have a units digit of 0, 1, 4, 5, 6, or 9.   The answer is 16,641.
<result>E</result>
If x = y^2, and x and y are positive integers, which of the following numbers could be the value of x?