Question 398592

In general to find the sum of all the numbers from 1 to N:

{{{1 + 2 + 3 + 4 }}}+ . . . . +{{{ N = (1 + N)*(N/2)}}}

{{{1 + 2 + 3 + 4 }}}+ . . . . +{{{ 122 = (1 + 122)*(122/2)}}}

so,

{{{ (1 + 122)*(122/2)}}}

{{{ 123*61=7503}}}........