If x, y, and z are positive integers such that x^2 + y^2 + z^2 = 3460, which of the following could be the values of x, y, and z?
I. x=21,y=42,z=36
II.x=20,y=41,z=30
III.x=20,y=42,y=36
Choose the most appropriate option
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 = 20, so x^2 will have units digit 0   y = 42, so y^2 will have units digit 4   z = 36, so z^2 will have units digit 6   III onlyalculate the units digit , the units digit will be 0   Test with options II and I, only option III will satisfy the condition , hence this will be our answer is option III only.
<result>C</result>
If x, y, and z are positive integers such that x^2 + y^2 + z^2 = 3460, which of the following could be the values of x, y, and z?
I. x=21,y=42,z=36
II.x=20,y=41,z=30
III.x=20,y=42,y=36