Let a 1 ,   a 2 ,   a 3 , … a n , … ,be in A.P. If a 3 + a 7 + a 11 + a 15 = 72 , then the sum of its first 17 terms is equal to :

Question

Let a 1 , &#160; a 2 , &#160; a 3 , &#8230; a n , &#8230; ,be in A.P. If a 3 + a 7 + a 11 + a 15 = 72 , then the sum of its first 17 terms is equal to :

Aicharya · Accepted Answer

a 3 + a 7 + a 11 + a 15 = 72 a 3 + a 15 + a 7 + a 11 = 72 a 3 + a 15 = a 7 + a 11 = a 1 + a 17 a 1 + a 17 = 36 S 17 = 17 2 a 1 + a 17 = 17 &#215; 18 = 306

Let a 1 ,   a 2 ,   a 3 , … a n , … ,be in A.P. If a 3 + a 7 + a 11 + a 15 = 72 , then…

Solution

Let a 1 , &#160; a 2 , &#160; a 3 , &#8230; a n , &#8230; ,be in A.P. If a 3 + a 7 + a 11 + a 15 = 72 , then…

Solution

Let a 1 , a 2 , a 3 , … a n , … ,be in A.P. If a 3 + a 7 + a 11 + a 15 = 72 , then…