UPSEE Solved Model Paper 2

The four terms are (a - 3d), (a - d), (a + d) and (a + 3d).
a - 3d + a - d + a + d + a + 3d = 16
4a = 16
a = 4
(a−3d)2+(a−d)2 + (a+d)2+(a+3d)2 = 84
4a2+20d2 = 84
d = 1, - 1
Therefore, the terms are 1, 3, 5, 7 or 7, 5, 3, 1.