Question

the sum of 15 terms of an ap is 240. then the 8th term is ---

Answer 1

the sum of 15 term=240
so, thesum of 1 term =240/15

sum of 8th term =240/15×8
=16×8=128

Answer 2

The 8th term is 16.

-----------------------------------------------------------------------------------

Let's understand a few concepts:

To solve the given problem we will use the following formulas:

• The sum of n terms of an A.P. is: $\boxed{\bold{S_n = \frac{n}{2}[2a+(n-1)d] }}$

• The nth term of an A.P. is: $\boxed{\bold{a_n = a + (n-1)d}}$

------------------------------------------------------------------------------

Let's solve the given problem:

The sum of 15 terms of an A.P. = 240

So, we get

$S_ 1_5 =\frac{15}{2}[2a+(15-1)d]= 240$

$\implies\frac{15}{2}[2a+(15-1)d]= 240$

$\implies\frac{15}{2}[2a+14d]= 240$

$\implies 15[a+7d]= 240$

$\implies a+7d= \frac{240}{15}$

$\implies a+7d= 16\:.\:.\:.\:.\:(1)$

Now,

The 8th term of the given A.P. will be,

= $a_8$

= $a+ (8-1)d$

= $a+7d$

• from equation  (1), we get

= $\bold{16}$

Thus, the 8th term of the A.P. is 16.

----------------------------------------------------------------------------

Learn more on brainly.in:

brainly.in/question/5666249

brainly.in/question/6288895