Answer:
100
Step-by-step explanation:
Given :
Terms ( n ) = 100
First term ( a ) = 100
Series = > 100 + 98 + 96 .......
Common difference ( d ) = 98 - 100 = > - 2
We know sum formula:
S_n = ( n / 2 ) ( 2 a + ( n - 1 ) d )
= > S_100 = ( 100 / 2 ) ( 200 + ( 100 - 1 ) - 2 )
= > S_100 = 50 ( 200 - 198 )
= > S_100 = 50 ( 2 )
= > S_100 = 100
Therefore, sum of first 100 terms is 100.
