卧室春竹

哦  YEAH!!!
           做题ING！！

VICTOR_JZG

让我一阵好找!
我来把它置顶!

辛苦了,lisaislisa,M022girl!

VICTOR_JZG

再顶!

mogama

6)WHAT IS THE NUMBER 108 MORE THAN TWO-THIRDS ITSELF

是否是这样
x-x*2/3=108
所以x=3*108=324

lisaislisa

6)WHAT IS THE NUMBER 108 MORE THAN TWO-THIRDS ITSELF 这个it self 就是指 the number so i assume it means 108>2/3*X X<162 ^^

mingja

2).(1.00001)^2*(0.99999)^2-(1.00002)^2*(0.99998)^2
my ans：-3*(10)^(-10)
[思路] (1+10^-5)^2*(1-10^-5)^2-(1+2*10^-5)^2*(1-2*10^-5)^2
=(1-10^-10)^2-(1+4*10^-10)^2
=(2-5*10^-10)(3*10^-10)
怎么算不到作者答案呢?...;p

I tried and get the same answer.


[思路] (1+10^-5)^2*(1-10^-5)^2-(1+2*10^-5)^2*(1-2*10^-5)^2
=(1-10^-10)^2-(1+4*10^-10)^2
={(1-10^10)+(1-4*10^-10)}{(1-10^10)-(1-4*10^-10)}
={1-10^10+1-(4*10^-10)}{1-(10^10)-1+(4*10^-10)}
={2-(5*10^-10)}{3*10^-10}


I think the original calulation that have -3*(10)^(-10) as the answer
missed the square part after

(1-10^-10)^2-(1+4*10^-10)^2
in which case you get
(1-10^-10)-(1+4*10^-10)
=-3*(10)^(-10)


6)WHAT IS THE NUMBER 108 MORE THAN TWO-THIRDS ITSELF? I CHOOSE 162, 不知对否
[思路]应该是小于 162
As the question provides , 108 should be more than 2/3 of the number , while 108 is exactly 2/3 of 162 .Therefore , the answer should be less than 162.


If X is the number

x=108+{(2/3)x}

x=324


11)一对夫妻生了4个小孩，问两男两女的概率。 选3/8
[确认]C(4,2)/2^4=3/8

Can somebody explain this please? Why divide by 2^4?

lisaislisa

6)WHAT IS THE NUMBER 108 MORE THAN TWO-THIRDS ITSELF? I CHOOSE 162, ------------------------- different understanding here , i am afraid i assume 'itself' is the same with ' the number' therefore , 108>2/3*X X<162 11)一对夫妻生了4个小孩，问两男两女的概率。 选3/8 [确认]C(4,2)/2^4=3/8 ------------------------------------- 2^4 , once a baby born , it can be a boy or a girl ,and in this case , 4 baby born ... C(2,4) means we assume two of them are boys (or girls , whatever) , then obviously the other two are girls ( or boys ) ^^

Mush

6)WHAT IS THE NUMBER 108 MORE THAN TWO-THIRDS ITSELF? I CHOOSE 162,
-------------------------
把这个问题变成一般陈述句为
the number is 108 more than 2/3 itself

这样不就是x-108=x2/3
x=324.这个数为324

lisaislisa

I know what makes the difference !
Your interpretation is the number is 108 MORE than 2/3 itself
but mine is............the number is 108 MORE THAN 2/3 itself
but it's nonsense
My misunderstanding ....thx Mush ^^

qqks

14)During a trans-atlantic trip ticket, 20% held round-trip and with cars aboard, 60% held round trip ticket with no car aboard. ask the total percentage of persons held round-trip ticket.
30%, 60%, 66-1/3 %
hope somebody help me. No answer is bigger than 66.3333%
------------------------------------------------
[思路]no idea...
[08]

我算的是50%， 不知道对不对