a-b = b-c = c-d = d-e = k olsun
d = k + e
c = k + d = k + (k + e) = 2k + e
b = k + c = k + (2k + e) = 3k + e
a = k + b = k + (3k + e) = 4k +e
a + b + c + d + e = 170
(4k + e) + (3k + e) + (2k + e) + (k + e) + e = 170
10k + 5e = 170
2k + e = 34
a + e = (4k + e) + e = 4k + 2e = 2(2k + e) = 2.34 = 68