If integer k is equal to the sum of all even multiples of 25 between 295 and 615, what is the greatest prime factor of k? Choose the correct option:
A) 5
B) 7
C) 11
D) 13
E) 17
if we break down what the stem is asking what is the sum of all mult of 50 between 300 and 600.   using arithmetic progression to find n : 600 = 300 + (n - 1) 50   300+ 50 = 50n   350 = 50n =&gt; n = 7   the sum would be: 11* mean   mean = [600 + 300] / 2 = 450   7*450 = 4950   7
<result>B</result>
If integer k is equal to the sum of all even multiples of 25 between 295 and 615, what is the greatest prime factor of k?