Hard GRE Math Arithmetic Problems Hello everybody. I think it’s time for all of you to do a little more work. Here are three challenging Level 5 GRE arithmetic questions. Note that all three of these questions are free response questions (or grid-ins). Please feel free to post your solutions or attempted solutions in the comments below and we can discuss the best way to solve each of these problems. I will post full solutions tomorrow. Level 5 GRE Arithmetic Problems If n is a positive integer such that the units (ones) digit of n2 + 4n is 7 and the units digit of n is not 7, what is the units digit of n + 3? The sum of the positive odd integers less than 200 is subtracted from the sum of the positive even integers less than or equal to 200. What is the resulting difference? The positive number k is the product of four different positive prime numbers. If the sum of these four prime numbers is a prime number greater than 20, what is the least possible value for k? More Hard GRE Math Practice Problems For many more hard GRE math problems like these, each with several fully explained solutions, check out 320 GRE Math Problems arranged by Topic and Difficulty Level. And if you think your friends would like to try these problems, please share: Talk soon! Comments comments