2_22

The program produces the answer list in reverse order
because it takes the first item from the things list
and makes it the first item of the answer list. The
second item when squared and consed into the answer list
is now at the first position in the answer list and so
on. Thus the final answer list is in reverse order.

The second version of his program does not give him the
answer he wants because cons takes two arguments, an item
and a list and puts the item in the front of the list. By
doing (cons answer (square (car things))) he creates a
list of lists every time answer is consed into the LIST
(square (car things)).