Question

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

Answer 1

Answer:

a= 10

d = -4

n = 16

so,

Sn = n/2 ( a+ (n-1) d)

Sn = 16/2 ( 10 + ( 16 - 1) × -4)

Sn = 8 ( 10 - 60)

Sn = 8 × 50

Sn = 400

pls mark me the brainiest if it helped u

Answer 2

Sn = n/2 ( 2a + (n-1)d)
Here n= 15. a = 10. d = 6-10=-4

Substituting
Sn = 15/2( 2(10) + (15-1)(-4))
= 15/2 (20 -56)
= 15 * (-36) /2
= 15 *(-18)
= -270

Hope this answer helps you