Question 455531


first term, {{{a=12}}}
number of terms, {{{n=14}}}
difference between any two adjacent terms, {{{d=2}}}

last term, {{{L= a+(n-1)d=12+(14-1)2=12+26=38 }}}


{{{sum= n(a+L)/2 }}} which is


{{{sum= 14(12+38)/2 }}} 


{{{sum= 14(50)/2 }}} 

{{{sum= 7(50) }}} 

{{{sum= 350 }}}