Sure, the answer can't be even because an even number of quarters comes out as a value ending in "0" so when you add any number of dimes you can't come out with a 5 in the units place. Since the total value is $3.25, we have an odd number of quarters.
Did you do it algebraically? If so, you restated (Pillar II again) the information as .25n + .10(22-n) = 3.25 and solved for n. There are a couple of places you can make simple algebra errors so watch out when you multiply .10 times (22-n). You need to end up with 2.2 -.1n. Then you'll probably clear all the decimals. So be very careful.
Let's do it by substitution. Where do you start?
C. Nine quarters gives us $2.25.
That means there has to be too
many (13) dimes left because the
total will be more than $3.25. If
you noticed that there can't be an
even number of quarters, you'd go
directly to A. If not, you'd
calculate, eight quarters is $2.00
and see that there isn't any
number of dimes that can give you
$3.25 leaving you with A. Be sure
to check your calculations by
doing (A). Seven quarters are
$1.75 plus (22-7) 15 dimes is
$3.25. Do you think this way was
easier than algebra? Practice it.
You'll like it.