For the GRE’s quantitative reasoning section, you will have to show your ability to work with both fractions and percents. Occasionally, problems will combine both, but because percents and fractions are closely related, even problems that use both can be solved. The GRE guides at Testmasters bring you today a walkthrough of a common type of percent and fraction problem you could see on the exam.
In an undergraduate program at a university, there were 300 graduates one year. By the time the class reunion rolled around 10 years after graduation, of those 300 students, went on to get their masters degrees, and of those who earned a masters, another 25% continued onto higher education and got their doctorate degrees. Of the 300 original graduates from the undergraduate university program, how many had a doctorate degree at the reunion?
First, break this problem down into its components. Any time you see the word “of” in a fraction or percent problem, it indicates multiplication. Start with the initial amount of graduates and find the number who got their masters. Because the problem indicates that of the original 300 got a masters degree, turn this into a math equation by replacing the word “of” with a multiplication sign. This makes sense, because in a fraction problem, fraction times the whole is equal to the part.
This means that at the reunion, 100 had at least a masters degree.
Next, the problem says that of those who got a masters degree, 25% went on to get a doctorate. Rather than using 300 for the whole, the whole group in this part of the problem is the 100 who got a masters degree. With percent problems, the same formula used for fraction problems applies.
At the 10-year reunion, 25 of the original graduates will have a doctorate.
Now, you can conquer percent and fraction problems by remembering the equations: