Question 355683
Hi,
*Note: For an Arithmetic progression

{{{a[n] = a[1] + (n-1)d}}}  and {{{Sum[n] = (n(a[1] + a[n]))/2}}}
.
d = 23
{{{a[10] = 576 + 9*23 = 783 }}}
.
{{{Sum[n] = (n(a[1] + a[n]))/2}}}
.
{{{Sum[10] = (10*(576 + 783 ))/2}}}