If x, y, and z are positive integers such that x^2 + y^2 + z^2 = 64,470, which of the following could be the values of x, y, and z?
I. x = 115, y = 146, z = 173
II. x = 114, y = 142, z = 171
III. x = -115, y = 146, z = 173
Answers.
A) I only	B) II only	C) III only	D) I​ and II	E) I and III
10 sec answer if you know how to find the units digit of a number   The number given is of the form of square, so calculate the units digit - Here your objective is to find the sum where last digit is 0   x = 115, so x^2 will have units digit 5   y = 146, so y^2 will have units digit 6   z = 173, so z^2 will have units digit 9   Calculate the units digit , the units digit will be 0   Here III) option gives x=-115..(115^2) and(-115^2) are equal.   Hence this will be our answer is option I and III.
<result>E</result>
If x, y, and z are positive integers such that x^2 + y^2 + z^2 = 64,470, which of the following could be the values of x, y, and z?
I. x = 115, y = 146, z = 173
II. x = 114, y = 142, z = 171
III. x = -115, y = 146, z = 173