Consider the sequence of sums $1,1+2,1+2+3$, $1+2+3+4,1+2+3+4+5, \ldots .$
(a) What happens to the terms of this sequence of sums as $k$ gets larger and larger?
(b) Find a sufficiently large value of $k$ that will guarantee that every term past the $k$ th term of this sequence of