Let a_1, a_2, a_3 be an arithmetic sequence. If a_4/a_2 = 2, find a_5/a_3.
a_1, a_2, a_3, ... can also be written as a_1, a_1 + d, a_1 + 2d... where d is the common difference of the sequence.
a_4/a_2 = (a_1 + 3d)/(a_1 + d) = 2
a_1 + 3d = 2a_1 + 2d
d = a_1
a_5/a_3 = (a_1 + 4d)/(a_1 + 2d)
= 5d/3d
= 5/3
+1223 
