Answer:

Step-by-step explanation:
We know that Mary has two twenty dollar bills, equaling to forty dollars in total.
So lets start on the first few things she buys, the berries, each costing 7.98 dollars and cents, since she only bought two, that means we need to multiply 7.98 by 2
==> 15.96 dollars and cents
Now we can take it out of forty.
$ 40.00
- $ 15.96
-------------------
$24.04
Now we only have 24.04 dollars and cents.
Now for the next few items, the peaches which costs 5.99 each, then since he only bought 3, we multiply 5.99 three times.
==> 17.97 dollars and cents
Now we can take it out of 24.04.
$24.04
- $ 17.97
--------------------
$6.07
Mary has 6 dollars and 7 cents in change.
You need to make a draw of the problem to understand what to do.
The height of the pyramid, and half the original base side length make a rectangle triangle, whose hypothenuse is the height of the lateral area of one of the pyramids faces, so we have. So we use Pythagoras:
hyp^2 = 11^2 + 14^2 = 317
hyp = 17.8 m
that is the height of the lateral area triangle
Now to find the area of the lateral area triangle, we have:
a = base*height/2 = 22*17.8/2
a = 195.8 m^2
that is the lateral area of the pyramid, 196 m^2