13. c. This uses the same principles as #10 in Test 1,
section 2. ^ is a function definition just as # was
a function definition. ^ means “take the value
after the ^ symbol, multiply it by 2, and divide
it by the value before the ^ symbol.” So,
h ^
g is
equal to two times the value after the ^ symbol
(two times
g ) divided by the number before the
^ symbol:
2
h g . Now, take that value, the value of
h ^
g , and substitute it for
h ^
g in (
h ^
g )^
h :
(
2
h g )^
h . Now, repeat the process. Two times the
value after the ^ symbol (two times
h ) divided
by the number before the symbol:
=
2
2
h g 2
=
h g 2
.
14. c. If four copy machines make 240 copies in three
minutes, then five copy machines will make 240
copies in
x minutes:
(4)(240)(3) = (5)(240)(
x )
2,880 = 1,200
x x = 2.4
Five copy machines will make 240 copies in 2.4
minutes. Since there are 60 seconds in a minute,
0.4 of a minute is equal to (0.4)(60) = 24 sec-
onds. The copies will be made in 2 minutes, 24
seconds.
15. d. 40% of
j = 0.4
j , 50% of
k = 0.5
k . If 0.4
j = 0.5
k ,
then
j =
0
0
.
.
5
4
k = 1.25
k .
j is equal to 125% of
k ,
which means that
j is 25% larger than
k .
