Question

The sum of 1st 3rd and 7th term of an Ap is 216 find the sum of 1st 13 term of the Ap

Answer 1

Answer:

936

Step-by-step explanation:

Hi,

Given that the sum of first, third and seventeenth terms of an AP is 216

Let the first term of AP be 'a'

Let the common difference of the A.P be 'd'

T₁ = a

T₃ = a + 2d

T₁₇ = a + 16d

T₁ + T₃ + T₁₇ = 216

3a + 18d = 216

a + 6d = 72

T₇ = 72

Sum of first 13 terms of A.P

= 13/2[2a + 12d]

= 13*T₇

= 13*72

= 936

Hope, it helps!

Answer 2

it seems the question is right