Question

To find the sum of consecutive integers, starting at 1, we use the formula n(n+1)/2 where n is the last number. Find the sum of the numbers from 1 to 100.

1 + 2 + 3 + ... + 100
A.101
B.1,001
C.5,000
D.5,050

Answer 1

substitute 100 to n

\[\implies \frac{100(100+1)}2\]
use your calculator

Answer 2

Thanks i got it :)