Question

The 13 th term of the ap is two times its 10 th term and 3 rd term is 6 note than two times its 6 th term find the sum of first five term of an ap

Answer 1

Answer:

60

Step-by-step explanation:

Let the first term be a and common difference be d.

As per the question,

a+12d = 2(a+9d)

=> 2a+18d-(a+12d) = 0

=> a+6d = 0 -----(1)

a+2d = 2(a+5d)+6

=> 2a+10d+6-(a+2d)=0

=> a+8d+6=0 -----(2)

Subtracting eq. (1) from eq. (2),

8d+6-6d=0

=> 2d+6=0

=> 2d = -6

=> d = -3

From equation (1), a = -6d = -6×(-3) = 18

Therefore, the first five terms = 18, 15, 12, 9 & 6.

And the sum of the first five terms = 60.

Please mark it as the brainliest answer for this question.