Question

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

Answer 1

Answer:

6/2(3+27). =3(30). Therefore, the sum of first six terms of an AP is 90.

Step-by-step explanation:

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Answer 2

Answer:

90 is the sum of first six term of the A.P

Step-by-step explanation:

Explanation:

Given , a = 3  and $t_{6}$ = 27

Here we can see that the first term $t_{1}$ = 3 and

the 6th term is $t_{6}$ = 27

Now we know the formula  sum of nth term which is

   $S_{n}$ =$\frac{n}{2} (t_{1}+t_{n} )$

Where , n is the number of term

and  $t_{n}$ is the last term .

Step 1:

        $S_{n}$=$\frac{n}{2} (t_{1}+t_{n} )$

Therefore we find sum of six term

⇒$S_{6} = \frac{6}{2} (t_{1}+t_{6} )$

put the value of $t_{1}$ and $t_{6}$ in the above equation

⇒ 3(3+27) = 90.

$S_{6} = 90$

Final answer :

Hence ,  the sum of first six term of the A.P is 90 .