Question

Question #0df0d

Answer 1

`171700`

Explanation:

`x=1+(1+2)+(1+2+3)+.....+(1+2+3+......+100)`

=`sum_{k=1}^100 (k*(k+1))/2`

=`1/2*sum_{k=1}^100 (k^2+k)`

=`1/2*((100*101*201)/6+(100*101)/2)`

=`171700`