文档介绍：新gre数学重要考点汇总
所以，从今日起，针对新版gre数学复****每天给考生整理一个重要考点，这些概念在考试中肯定会考到的。盼望考生能再接再厉，取得一个好成绩，突破新版gre数学难的逆境。
新版gre数学复****重要考点：Sum of mbers of an AP can be calculated from the average. the first number x = c-d(m-1)/2, and the n-th number is c+d(2n-m-1)/2, where c is the average of m numbers.
Example:
if the average of 15 consecutive integers is 20, then the first number x=20-1*(15-1)/2=20-7=13 and the last number (n=m=15) is 20+1*(2*15-15-1)/2=20+7=27.
if the average of 33 consecutive odd numbers is 67, then the first number x=67-2*(33-1)/2=67-32=35 and the last number (n=m=33) is 67+2*(2*33-33-1)/2=67+32=99.
Remember:
sum of the m numbers is c*m,where c is the average.
Sequence of Numbers
A sequence is a set of numbers that follow a fixed fixed pattern can be expressed by an equation or by a property.
Example:
A set of consecutive integers: 1,2,3,4,5(Fixed gap)
A set of consecutive even numbers:4,6,8,10,12 (Fixed gap)
A set of consecutive prime: 2,3,5,7,11(Fixed gap)
A set of consecutive power of 2:4,8,16,32,64(Fixed gap)
Remember:
A sequence can be in ascending or desceding order.
Mode
The mode of a set of numbers is the number that repeats the most in the set.
Example:
Mode of the set {1,2,3,2,4,5} is 2.
The set of numbers {1,2,4,1,2,3,6,8}has two modes