Percentage word problemsBefore you learn about percentage word problems, review Formula for percentage or you can use the approach that I use here. 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! 




