Question 980120

if an even number is {{{N}}},  then we have

{{{N = (First_ Even + Last _Even)/2 - 1}}}

{{{N = (2+100)/2 - 1 = 50}}}; so, there is {{{50}}} even numbers from {{{1}}} to {{{100}}}

{{{Sum = (number_ of_ integers) * (average_ of_ biggest_ and_ smallest)}}}

biggest even number is {{{100}}}, smallest is {{{2}}}, so average of biggest and smallest even number is {{{(100+2)/2=51}}}

then, the sum of first {{{50}}} positive {{{even}}} integers is {{{(50)(51) = 2550 }}}