Each week, we post a new Challenge Problem for you to attempt. If you submit the correct answer, you will be entered into that week’s drawing for two free Manhattan Prep GRE Strategy Guides.

Rebecca had 288 Facebook friends, and noticed that an equal number of these friends had birthdays in each of the twelve months of the year. Then, Rebecca approved many friend requests at once. After doing so, the number of Rebecca’s friends with birthdays in the last quarter of the year increased by 25%, the number of friends with birthdays in each month beginning with J increased by one-third, the number of people with birthdays in February was increased by 12.5%, the number of people with birthdays in March became of the new number of people with birthdays in February, the number of people with birthdays in April became five less than 75% of the new number of people with birthdays in February and March combined, the number of people with birthdays in May increased by 1, and the number of people with birthdays in August became one less than 20% greater than the new number of people with birthdays in May. Finally, September’s total increased to 6% less than one more than the new total for the month with the largest number of birthdays. Assuming no one de-friended her, after approving all her friend requests, how many Facebook friends did Rebecca then have?

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Here are two hilarious — but mathematically GRE-like — problems written by Manhattan GRE instructor Tommy Wallach.

As on the real GRE, both questions use the same set of two charts. The first question is multiple choice; the second requires you to enter your own answer. You may use a calculator.

1. If the five categories of irony were placed in the slice appropriate to them in the first chart, approximately what would be the internal angle of the slice labeled nostalgia, in degrees?

1. 7
2. 21
3. 25
4. 57
5. 70

2. If a hipster’s priorities were expressed as a percentage of 500 priority points, what would be the point difference between knowledge of craft beers and ironic attitude, rounded to the nearest tenth?

Give these problems a shot before reading further.

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Mnemonics or mnemonic devices are memory tricks to help us remember things like vocabulary words. However, many mnemonics are pretty cheesy — often involving the kind of jokes some people call “groaners.” For instance…

To abase is “to reduce or lower, as in rank, office, reputation, or estimation; humble; degrade.”

Here’s the mnemonic:

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