guggi2

ohh my typing is wrong it is not P(AUB) = P(A)xP(B) but P( A intersect B) = P(A)P(B)

there are 2 groups; the group of 3 people who get the award and the group of 2 people the get nothing. The total ways to separate 2 grouprs equal 5!/3!2!(=10) So each of 5!/3!2! will get the same situation which is 3 people will win the award. The possibility to win is 40% (=0.4) and to fail is 60%(0.6) This is an independent possibility (the way to win award doesn't affect each other) Use this theory: P(AUB) = P(A)xP(B) so the possibility for 3 people to win and 2 to fail is (0.4)(0.4)(0.4)(0.6)(0.6) but each possiblity has 10 pattern (from separate 5 people into 2 groups) the total possiblity is 10(0.4)(0.4)(0.4)(0.6)(0.6) = around 0.23

:p ohh yeah I forgot to divide 900 with 2 one more time. do this: from 110 to 1008, even numbers equals (1008-110)/2 +1 = 450 numbers each pair causes the result-2 450 numbers = 225 pairs sum = 225x(-2) = -450 I spent less than 1 min to get the first wrong anwer. Must be careful

c.-900

From Relative velocity : t(time they met) = s (length between 2 stations) / (Vp+Vq) [Vp+Vq is the relative velocity when they move to each othert] t = 2hr s=250 ,then (Vp+Vq) = 125 mile/hr (1) speed of train p when they met = 70mile/hr ,Since Vp=70, Vq is 125-70=55 mile/hr Now we know the speeds of both trains, then it's enough (2) When we talk about relative velocity, we use only the speed when they meet each other.Average speed cannot tell you exactly the speed when they meet. Average speed is originated from Total distance/ Total time. We cannot find the speed at any time between the distance. So (2) is useless information.

1.b because the McKay team had some good reasons to gainsay the skeptics. 2.e The skeptics tried to contradict MaKay team's evidence. 3.a ALH84001might have resulted form terrestrial contamination(on the earth). that means ALH84001 may not have originated on Mars.

there are 64 Ks.

Since the question guild "A certain clothes only can be paired to one tie", 5 clothes (4 free clothes +1 special cloth) 7 ties (6 free ties + 1 special tie) 1. choose 4 free clothes and 6 free ties = 6x4 = 24 ways 2. choose special cloth and tie = 1way 2 continuous steps will cause total 25 ways

I like this question. if interger x>1, x! is even. now we got 0! and 1! which are both equal 1, so (1) is not enoug. But (2) will help that x is even, then x is actually equal "0" So C

Ok If you got no idea that if 0

1) x^2>y^2 x^2-y^2>0 (x-y)(x+y)>0 then x>y or xy is out of the question caz the conditon is x 1.1 if y is positive, x is absolutely negative 1.2 if y is negative, (causing xY^2, then x must be a negative number so (1) is enought 2. x^3 then x so (2) is not enough

Is quadrilateral RSTV a rectangle? (1) The measure of (2) The measure of why the official answer is E

As we know not only ...... but also..... not merely .....but also..... not exclusively .......but also..... not simply ........but also....... but we don't use " not justly ...... but also..... because just is an adverb by itself so not just..........but....... ( Q1 tested u about parallelism) note: sometimes but also can be changed to ....but......as well. (it's optional)