Given Arithmetic Progression = -2, 0, 2, 4,.........
We have to find which term of the given A. P. is 80 and 102.
⇒ an = a + (n -1)d
Where a = -2
and common difference (d) = 0 - (-2)
= 0 + 2
= 2
Therefore,
80 = -2 + (n - 1)2
80 = -2 + 2n -2
80 + 2 + 2 = 2n
84 = 2n
n = 84/2
n = 42
So, 80 is 42nd term of the given A.P.
102 = -2 + (n - 1)2
102 = -2 + 2n -2
102 + 2 + 2 = 2n
106 = 2n
n = 106/2
n = 53
So, 102 is 53rd term of the given A.P.