if a=3 and t6=27,find the sum of the first six terms of the A. P. ​

1 thought on “if a=3 and t6=27,find the sum of the first six terms of the A. P. ​”

1. Given

   first term(a)= 3

   t₆= 27

   To Find

   we have to find first six terms of the A.P

   [tex]\sf\huge\bold{\underline{\underline{{Solution}}}}[/tex]

   first term (a)= 3

   t₆= 27

   t₆ can be written as : a+5d

   ↣a+5d= 27

   put the value of a

   ↣3+5d= 27

   ↣5d= 27-3

   ↣5d= 24

   ↣d=24/5

   We have to find sum of first six terms

   Sₙ=n/2 [2a+(n-1)d]

   ↣S₆= 6/2[2(3)+(6-1)24/5]

   ↣S₆= 3[6+5×24/5]

   ↣S₆=3[6+24]

   ↣S₆= 3(30)

   ↣S₆=90

   Hence,the sum of first six terms is 90.

   Reply