There are many word problems on the HiSET Math Exam, and
proportions can be a useful way to solve problems that
mention miles per hour, scale drawings, ratios and more.
Using Proportions to solve word problems. A proportion is a
comparison of two numbers. These are often written like fractions: if 4 out of 5 people have brown eyes, the proportion is written 4/5. Here are four problems that can be solved by setting up a proportion and then cross multiplying.
The scale drawing (1 in = 5 ft) of a bridge measures 3.5 inches. How
long is the actual bridge?
1 inch = 3.5 inches 5 feet ?? feet
Now multiply the diagonals:
5 x 3.5 = 1 x ??
17.5 = 1 x ??
Next divide:
17.5 / 1 = 17.5 feet
The actual bridge is 17.5 feet long.
Traveling at 40MPH how far can Joe travel in 25 minutes?
40 MPH means 40 miles per one hour, or 40 miles in 60 minutes.
40 miles = ?? miles 60 minutes 25 minutes
Now multiply the diagonals:
40 x 25 = 60 x ??
1000 = 60 x ??
Next divide: 1000 / 60
Answer: 16.67 miles Joe can travel 16.67 miles in 25 minutes.
If 8 peachs cost $2.00, what do a dozen peaches cost?
There are 12 peaches in a dozen.
8 peaches = 12 peaches $2.00 $ ??
Now multiply the diagonals:
$2.00 x 12 = 8 x ??
24 = 8 x ??
Next divide: 24 / 8
Answer: $3.00
A dozen peaches cost $3.00
The team has a win/loss ratio of 4/3. If they play 63 games,
how many should they win?
Looking at that ratio, if you win 4 games and lose 3, you have played a
total of 7 games. So they win 4 out of 7 games.
4 wins = ?? wins 7 games 63 games
Now multiply the diagonals:
4 x 63 = 7 x ??
252 = 7 x ??
Next divide: 252 / 7
Answer: 36
The team wins 36 games out of 63 played.
Algebra makes up about 40% of the HiSET Math Exam. Be sure
to get comfortable with some of the basics, like solving an
algebraic equation.
Solving an Algebraic Equation.
Your goal is always to get “x” by itself.
Example: 5x + 4 = 34
First get rid of anything added or subtracted to x. In this problem
subtract away that 4 from both sides of the equal sign.
5x + 4 = 34
-4 -4
5x + 0 = 30
Next divide or multiply to get rid of the number next to the X.
5x = 30 5 5
x = 6
Example: 6x – 7 = 11
Add 7 to both sides + 7 = +7
(Remember you want 6x + 0 = 18
that 7 to turn into a zero)
6x = 18 Divide by the 6 6 6
Answer: x = 3
Just keep focusing on getting “x” by itself, and always make those
moves to both sides of the equal sign.
Math can seem tricky, but a good explanation helps a lot.
Nothing beats help in-person, so finding a tutor, or attending
Women In Charge may be just the help you need!
