Welcome back! If you haven’t had a chance to try your hand at this week’s Brain Twister, head back to the original post so you don’t accidentally see the answer here. Question A “phrase” is made up of the first seven letters of the alphabet so that each letter appears exactly once. The “phrase” […]

# Archive | Math Concepts

## Magoosh Brain Twister: Going Through a Phrase

Let the brain twisting commence! A “phrase” is made up of the first seven letters of the alphabet so that each letter appears exactly once. The “phrase” must contain at least two “words”, which must contain at least two letters. For instance, ABC DE FG and AB CDE FG are distinct “phrases”. How many […]

## Magoosh Brain Twister: Siding with the Polygon – Explanation

Welcome back! Today, we finally answer Tuesday’s Brain Twister challenge: Question In regular Polygon Q the ratio of the length of the longest line that can be drawn between two vertices to the length of any one side is greater than 2. A The number of sides of Polygon Q B 6 Answer […]

## Magoosh Brain Twister: Siding with the Polygon

Let’s jump right in to the brain twisting fun: In regular Polygon Q the ratio of the length of the longest line that can be drawn between two vertices to the length of any one side is greater than 2. A The number of sides of Polygon Q B 6 Good luck! And don’t […]

## GRE Quantitative Comparison Geometry Practice Problems

Here is a batch of 7 practice QC questions. Explanations will come at the end of the article. 1) In the diagram, AC = 6. CE = 12, DF = 4, and AB is parallel to DE. 2) 3) In the diagram, JL = 4 and JK = 6. 4) In […]

## FAQ: Should I Study Probability?

I have 30 days to the test and am terrified about probability…what should I do? There is perhaps no other topic on the GRE math that instills as much dread in students as does probability. Understandably, students will obsess over this topic more than they will other topics. However, such an approach won’t only lead […]

## Magoosh Brain Twister: Factorial Fun – Explanation

Welcome back! If you haven’t tried your luck with this week’s brain twister (or if you need a refresher), head back to the original post before checking out the answer. No cheating! 🙂 Question How many positive values of x exist if n is a positive integer and 10 < x < 100? n […]

## Magoosh Brain Twister: Factorial Fun

Ready to twist your brain? Check out this week’s numeric entry challenge: How many positive values of x exist if n is a positive integer and 10 < x < 100? n = [x! – (x – 2)!]/(x – 1)! Numeric Entry: __________ See you on Thursday for the answer and explanation!

## Magoosh Brain Twister: Variable Cloudiness – Answer and Explanation

Take a moment to refresh your memory, then jump into the explanation. Question If a – j are distinct positive integers, what is the units digit of the lowest possible value of a^b x c^d x e^f x g^h x i^j? (A) 0 (B) 1 (C) 2 (D) 4 (E) 8 Answer and […]

## Magoosh Brain Twister: Variable Cloudiness

It’s Brain Twister week again! Get ready to train your brain. If a – j are distinct positive integers, what is the units digit of the lowest possible value of a^b x c^d x e^f x g^h x i^j? (A) 0 (B) 1 (C) 2 (D) 4 (E) 8 Good luck, and don’t […]