If x is a sum of all even integers on the interval 13...61 and y is their number, what is the GCD (x, y)?	Select the correct option.
A) 1	B) 13	C) 26	D) 24	E) 1014
x = 14 + 16 + ... + 60 = (largest + smallest)/2 *(# of terms) = (14 + 60)/2*24= 37*24.   GCD of 24 and 37*22 is 24.   Answer: 24.
<result>D</result>
If x is a sum of all even integers on the interval 13...61 and y is their number, what is the GCD (x, y)?