Explanation:
The formula for calculating the sales price of an item is:
s
=
p
−
(
p
×
d
)
Where:
s
is the sales price: what we are calculating in this problem.
p
is the regular price of the item: $40 for this problem.
d
is the discount rate: 45% for this problem. "Percent" or "%" means "out of 100" or "per 100", Therefore 45% can be written as
45
100
.
Substituting and calculating
s
gives:
s
=
$
40
−
(
$
40
×
45
100
)
s
=
$
40
−
$
1800
100
s
=
$
40
−
$
18
s
=
$
22
