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# Archive | Series and Sequences

## Magoosh Brain Twister: Series Fun – Explanation

Question Here’s the question from Monday: The sum of m consecutive integers is 8. If the sum of n consecutive integers is m, what is the value of n? (A) 15 (B) 16 (C) 31 (D) 32 (E) Cannot be determined by the information provided.   Answer and Explanation The trick here is taking into […]

## Magoosh Brain Twister: Series Fun

As I promised, the Brain Twister is back in a bi-weekly format. Here is one that looks innocuous enough, but once you toy around with it for a few seconds you’ll see it’s anything but easy. The sum of m consecutive integers is 8. If the sum of n consecutive integers is m, what is […]

## Math Challenge Problem – A “Mean” Series

Set S consists of consecutive positive integers. If the lowest integer in Set S is 1 and the sum of the integers of Set S is 231, what is the median of Set S? 10.5 11 12 13 22   Explanation: One way to go about approaching this question is to try adding up consecutive […]

## GRE Math Video Lessons: Advanced Series and Counting

What is the sum of the first 50 positive integers?  (A)  1000 (B)  1225 (C)  1275 (D) 1400 (E)  1450 This is a daunting question, perhaps akin to the question that asks about two trains traveling at varying rates headed in the same direction. Just like the speeding locomotive question, this type of question should […]

## GRE Math Video Lessons: Series and Counting Basics

A relatively popular concept on the GRE math is series – when you have a list of numbers that follow a certain pattern(e.g. consecutive numbers). Usually, the question will ask you to add up all the numbers that are part of the series. Today, we are not going to go quite so far. Instead, we are going […]