Question

For an arithmetic progression,the first term is 14 and the last term is 212 ..if sum of all this terms is 11300, find the numbers of terms and common difference.​

Answer 1

Answer:

Please refer to the above image attached.

You will understand.

Thank you.

Answer 2

Answer:

n = 100

d = 2

Step-by-step explanation:

The sum of all term ( $s_{n}$) = 11300 .

$s_{n}$ = n/2 ( first term + last term )     ( n = no of terms )

⇒ 11300 = n/2 ( 14 + 212 )

⇒ n = 100

$a_{n} = a_{1} + (n - 1 )d$

$a_{n} = n^{th}$ term which is to be find.

$a_{1$ = first term.

d = common difference.

212 = 14 + ( 100 - 1 ) d.

d = $\frac{198}{99}$ = 2