Question

The sum of 1st, 3rd and 17th term of an ap is 216. Find the sum of the 13 terms of the A.P?

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

Answer:

936

Please see the attached image for explanation