The sum of first 16 terms of the AP 10, 6, 2, ... is

Question

Philoid · Accepted Answer

Here, first term = 10

Common difference = d = 6 - 10 = - 4

Sum of first n terms of an AP is

S_n = [2a + (n - 1)d]

∴ S₁₆ = [2(10) + (16 - 1)(-4)]

= 8 × [20 - 60]

= 8 × (-40)

= - 320

Thus, sum of 16 terms of this AP is - 320.