错选a,根据句意a complex修饰的是center,所以主语依然是programs,需要复数。。。。The Sports Medicine Programs
2 married couple can be included in 5c1,no. of ways selecting a couple, * 8c1, no. of ways selecting the third person,=5 * 8=40
从十个人里任意选三个人的集合用combination公式所以就是:10C3 = 120
但需要再减去有夫妻的组合,有5x8=40种可能
所以120-40=80
么想到假命题,字面意思是作者假设了一个结论想,然后意图用这个结论提供证据给这个假设以求证明这个假设是对的,其实想想就是作者干的事,罗里八嗦说了些废话,一点价值没有,也没给解释。
make sure you check if the numbers are integers, negative, positive, nonnegative and stuff
STATEMENT (1) The length of one leg is 3/4 the length of the other.
let the length of one leg = 4 than other = 3
area = 6
lenght of one leg = 8 other = 6
area = 24
INSUFFICIENT
STATEMENT (2) The length of the hypotenuse is 5.
--sides of the triangle are integers
hypotenuse = 5
the only possible integer values of legs are 3 and 4 (3,4, and 5 Pythagorean triplet)
--area of triangle = 6
SUFFICIENT
combining both statements together
--we know line passes through (0,0) and (1,n+2)
the slope of the line k = n+2
equation of line k -- (y-0) = (n+2)(x-0) -- y =(n+2)x
line k passes through (n,-1)
-1 = (n+2)n
n2n2+2n+1 = 0
(n+1)2(n+1)2 = 0
n = -1
slope of line = n+2 = -1+2 = 1
Is the slope of line k greater than zero?---YES
(1)|x|+|y| =1图像是个菱形,pq两个点可以在任何线上,斜率不固定
(2)|x+y|=1图形是两条平行的直线,pq只要在不同的直线上斜率就不固定
记得尝试枚举法和代入法
记得考虑分数和负数情况
AB 本质不对。 C是加强。E矛盾。蒙了个D。从来没见过这么赤裸裸的正确答案。
求的是现在的价值,现在的价值可以被看成一个整体的算是,不用非要求出本金和时间。
假设现在是x,则一年以前是x/1.2,1年以前拿掉了600 (x/1.2-600)*1.2=(1-0.12)x
make sure you check if there are only two kinds of newspaper read by people in that town!!
d的范围是(42500~34300),p的范围是(85.5~86.4),d/p的范围是(42500/86.4~43400/85.5)=(491.89~507.60),没法确定是否每个都在5~500之间。
集合子集的个数=2^n, 包含集合本身和空集。n等于元素的个数。一个集合中,任何两个元素都认为是不相同的,即每个元素只能出现一次。
运用排列组合的方法:从有n个元素的集合中抽出m个元素,构成的子集数=C(n,m)。
(1)从集合A里抽2个元素能构成6个子集,C(n,2)=6, n=4, A里元素的个数为4.
(2)集合A总共有16个子集,包括空集和集合本身,2^n=16, n=4,A里元素的个数为4.
There is no linguistic census in France, as there is in Britain, a fact that makes it difficult to estimate
同位语从
idiom: there were no X's or Y's.
so as to 的主语是句子的主语,压土机本身不会浪费水
waste water is done by the whole action
You are comparing actions, so you must use "just as."
3个连续的整数必有一个能被3整除,因为已经形成了一个3的循环;2个连续的偶数=4个连续的整数必有一个能被4整除,一个能被2整除,即乘积能被24整除
(2)2个连续的奇数+中间一个偶数必有一个能被3整除,偶数能被2整除,即乘积能被6整除,不一定能被24整除。
杨颖萱