Question

the sum of 5 terms of an A.P. is same as the sum of its 11 terms then sum of 16 terms is​

Answer 1

Answer:

Step-by-step explanation:

Sum of 5 terms of an AP = 5/2×[2a+4d]

=5(a+2d)

=5a+10d

Sum of 10 terms of an AP=10/2×(2a+9d)

=10a+45d

Sum of 16 terms of AP =16/2×(2a+15d)

=16a+120d

Now,according to the question,

5a+10d=10a+45d

5a=-35d

a = -7d.

So,S16=16(-7d)+120d

=-112d+120d

=8d

From value of d it can be calculated.

Answer 2

Answer:

8d

Step-by-step explanation:

this the answer to this question