Percentage word problems
Before you learn about percentage word problems, review
Formula for percentage or you can use the approach that I use here.
Example #1:
A test has 20 questions. If peter gets 80% correct, how many questions did peter missed?
The number of correct answers is 80% of 20 or 80/100 × 20
80/100 × 20 = 0.80 × 20 = 16
Recall that 16 is called the percentage. It is the answer you get when you take the percent of a number
Since the test has 20 questions and he got 16 correct answers, the number of questions he missed is 20 − 16 = 4
Peter missed 4 questions
Example #2:
In a school, 25 % of the teachers teach basic math. If there are 50 basic math teachers, how many teachers are there in the school?
I shall help you reason the problem out:
When we say that 25 % of the teachers teach basic math, we mean 25% of all teachers in the school equal number of teachers teaching basic math
Since we don't know how many teachers there are in the school, we replace this with x or a blank
However, we know that the number of teachers teaching basic or the percentage = 50
Putting it all together, we get the following equation:
25% of ____ = 50 or 25% × ___ = 50 or 0.25 × ____ = 50
Thus, the question is 0.25 times what gives me 50
A simple division of 50 by 0.25 will get you the answer
50/0.25 = 200
Therefore, we have 200 teachers in the school
In fact, 0.25 × 200 = 50
Example #3:
24 students in a class took an algebra test. If 18 students passed the test, what percent do not pass?
Set up the problem like this:
First, find out how many student did not pass.
Number of students who did not pass is 24 − 18 = 6
Then, write down the following equation:
x% of 24 = 6 or x% times 24 = 6
To get x%, just divide 6 by 24
6/24 = 0.25 = 25/100 = 25%
Therefore, 25% of students did not pass
If you really understand the percentage word problems above, you can solve any other similar percentage word problems.
If you still do not understand them, I strongly encourage you to study them again and again until you get it. The end result will be very rewarding!

Sep 01, 18 04:07 PM
These heart of algebra questions will help you prepare to take the math portion of the SAT
Read More
New math lessons
Your email is safe with us. We will only use it to inform you about new math lessons.