Find the sum of the first 100 terms of the arithmetic sequence with the first term 2 and the common difference 5.
First term = 2
100th term = 2 + 5(100 - 1) = 2 + 5(99) = 497
Sum =
[first term + 100th term ] * ( number of terms) / 2 =
[ 2 + 497 ] / (100) /2 =
499 * 50 =
24950
