Yesterday, we posted a GMAT practice question on Facebook. It got a lot of attention and many responses. Here it is again:
Our Facebook audience mostly answered A, with a few votes for D. The correct answer is indeed A, and here’s why…
- Statement (1) is exactly what is needed – it gives you a precise value for . Statement (1) is sufficient, so eliminate answer choices C and E.
- Statement (2) alone, however, leads to two possible values for b, because you’d have to substitute the square roots of 25 for a, and those square roots are BOTH positive AND negative 5 (remember this! The GMAT likes
If you need help with your GMAT prep, we’ve got you covered. Now is your chance to see one of our GMAT experts in action, breaking down the GMAT exam and introducing you to proven Kaplan methods and strategies that will allow you to dominate your competition on GMAT Test Day.
If you attended any of the free GMAT practice tests that we held recently, then you’ve already met some of our GMAT experts. What better way to continue your GMAT prep than to attend a free, live, online session that’s focused on introducing you to the most efficient approach to every question type that you’ll see on the GMAT?
Here’s an example of the type of questions you’ll see in our upcoming GMAT Sample Class:
The youngest of 4 children has siblings who are 3, 5, and 8 years older than she is. If the average (arithmetic mean) age … Read full post
Exponent questions are among those that give GMAT-preppers the most difficulty. The key to answering exponent questions correctly is to remember all of the rules you must follow. For example, knowing that ab x ac = ab+c, and ab x cb = (ac)b will be essential to answering exponent questions correctly.
However, you also want to avoid common exponent mistakes. This is especially important because wrong answer choices in exponent questions, as with the rest of the GMAT, will be based on common test-taker errors.
The most common mistake test-takers make on exponent questions is to erroneously believe that ab + ac = ab+c. Remember, exponent rules refer to multiplication and division, not addition and subtraction. When you encounter an exponent question on addition or subtraction, you will usually need to factor out like terms in order to simplify. … Read full post
Probability questions can be among some of the more advanced and trickier problems you’ll face on the GMAT Quantitative section. Be sure to pay attention to the wording of word problems such as this one; in this case when asked about a scenario with “at least twice”, it will be more efficient to solve for that NOT happening and subtract from 1 (since the probability of something happening plus the probability of that same thing NOT happening should add up to 1, or 100%.)
A fair coin is tossed five times. What is the probability that it lands heads up at least twice?
The key phrase to solving this sample GMAT problem is ‘at least twice.’ This means that out of our five flips, two, three, four and five heads are all desired outcomes. On problems such … Read full post
Try this advanced GMAT probability question, testing your knowledge of the ins and outs of how probability works.
The events A and B are independent. The probability that event A occurs is 0.6, and the probability that at least one of the events A and B occurs is 0.94. What is the probability that event B occurs?
In order to find the probability that event B occurs in this problem, we need to set up and equation that includes the probabilities we are given and allows us to solve for B. We are told that the probability that at least one of A or B occurring is 0.94. ‘At least one of A or B’ means that an outcome is desired if A occurs and B does not, B occurs and A does not or A and … Read full post
What should you do when you see a GMAT problem asking you for the average rate over an entire journey? Try your hand at this problem and let’s see.
A canoeist paddled upstream at 10 meters per minute, turned around, and drifted downstream at 15 meters per minute. If the distance traveled in each direction was the same, and the time spent turning the canoe around was negligible, what was the canoeist’s average speed over the course of the journey, in meters per minute?
In average rate problems many students forget that average rate means total distance divided by total time and not the average of the rates. This is especially true on problems, such as this one, that give the test-taker two rates, but no distances and no times. When this occurs, the most concrete strategy, … Read full post
Dealing with prime numbers and prime factors is an essential GMAT skill. Technically it is a skill we learned as early as elementary school/early school age, however just because it was learned in childhood does not mean that these questions are necessarily easy for GMAT test-takers. First of all, dealing with prime factors may not be something we do on a daily basis, so you’ll want to be sure you practice during your studies. Secondly, sometimes the wording or steps along the way can be challenging on the GMAT, not to mention the time limit. Here is a fairly straightforward question, though it may take some time to work through.
What is the smallest positive integer that is a multiple of 18, 20, 24, 25 and 30?
While taking each answer choice, starting with the smallest, and … Read full post
GMAT Data Sufficiency questions can take simple concepts like averages and have test-takers pausing or falling into traps because of the way they are worded, and the fact that you have to keep in mind what your goal is with Data Sufficiency—to find out whether or not you have sufficient information to answer the question!
Each of the 8 numbers s, t, u, v, w, x, y and z is positive. Is the average (arithmetic mean) of s, t, u, v, w, x, y and z greater than 46?
(1) The average (arithmetic mean) of s, t, u, v and w is greater than 74.
(2) The average of x, y and z is greater than 120.
Before evaluating the statements, you should reword the question. We are asked if the average of a list of numbers is greater than 46. Since average is equal to the … Read full post
When working on the GMAT quantitative section, it is always important to remember that the questions are written so that they can be completed within about a two-minute timeframe. If you encounter a problem and the math seems as if it will take more than two minutes to do, it generally means that either you made an error or a faster way to solve exists. One of the most frequent cases in which the latter occurs is on problems that involve multiplication, since there are no calculators on the GMAT.
Unlike long division, which can be very useful on the GMAT, longhand multiplication is almost never necessary. Instead you should always look for shortcuts to solve. Not only will this be quicker, but it will also provide fewer opportunities for careless errors.
One such shortcut is prime factorization. If a problem asks you to multiply 525 by 16, you … Read full post
Knowing how to use the distance = rate x time formula in various permutations will help you tremendously on the classic GMAT speed word problems. Just remember that when asked about average rate over an entire journey, you must think about total distance and total time over that journey….
A car drove from Town A to Town B without stopping. The car traveled the first 40 miles of its journey at an average speed of 25 miles per hour. What was the car’s average speed, in miles per hour, for the remaining 120 miles if the car’s average speed for the entire trip was 40 miles per hour?
To solve this problem, you must remember that average speed means total distance divided by total time over an entire journey, and is not the average of the speeds. … Read full post