Question

Find the sum of the A.P. 34 +32 +30+ ....+10​

Answer 1

The given arithmetic series is 34 + 32 + 30 + .....+ 10. Here a = 34, d = 32-34 = -2 and l = 10 Let the given series contain n terms. Then,

Answer 2

10 = 34 -2n+2

13 = n

Now sum

Sn=n/2(a+l)

Sn=13/2(34+10)

Sn=286

Sum is = 286