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<div style="margin: 0in 0in 0pt">7-Q2
If 2 different representatives are to be selected at random from a group of 10 employees and if p is the probabitily that both representatives selected will be women, is p>1/2?
(1)More than of the 10 employees are women.
(2)The probability that both representatives selected will be men is less than.

<div style="margin: 0in 0in 0pt">7-Q3
Material A costs $3 per kilogram, and material B costs $5 per kilogram. If 10 kilograms of material K cosists of x kilograms of material A and y kilograms of material B, is x>y?
(1)y>4
(2)The cost of the 10 kilograms of material K is less than $40

<div style="margin: 0in 0in 0pt">7-Q4
For a recent play performance, the ticket prices were $25 per adult and $15 per child. A total of 500 tickets were sold for the performance. How many of the tickets sold were for adults?
(1)Revenue from ticket sales for this performance totaled $10500
(2)The average(arithmetic mean) price per ticket sold was $21

<div style="margin: 0in 0in 0pt">7-Q8
The infinite sequence a1,a2,a3,...,an,...is such that a1=2, a2=-3, a3=5, a4=-1, and an=a(n-4) for n>4. What is the sum of the first 97 terms of the sequence?
 A.72   B. 74   C.75   D.78   E.80

<div style="margin: 0in 0in 0pt">7-Q14
If a code word is defined to be a sequence of different letters chosen from the 10 letters A,B,C,D,E,F,G,H,I,and J, what is the ratio of the number os 5-letter code words to the number of 4-letter code words?
A.5 to 4   B. 3 to 2   C. 2 to 1   D. 5 to 1   E.6 to 1 

<div style="margin: 0in 0in 0pt">7-Q22
The number of defects in the first five cars to come through a new production line are
9,7,10,4 and 6, respectively. If the sixth car through the production line has either 3, 7 or 12 defects, for wihch of theses valurs does the mean number of defects per car for the first six cars equal the median?
 I.3   II.7   III.12 </div><div style="margin: 0in 0in 0pt">A. I only   B. II only   C.IIIonly   D. I and III only   E. I,II and III</div><div style="margin: 0in 0in 0pt"> </div></div></div></div></div></div>
提问时间:2010-01-17 16:40:12提问者: Kathy00097 [初中生]
最佳答案

1:10个里面选2个代表,(2 different representatives )=不是一个人,选出同时是2个女人的情况>1/2

如果是大于1/2,女人个数=5的话是0.222的可能,所以肯定大于5,应该最少7个人才行,自己推吧,条件2=男人最多6个,条件一+条件2=再临界条件下总共13人了

2:Given:
x+y=10
3x + 5y is K's cost
A) y > 4, y could be 5,6,7,8,9,10. Not sufficient

B) The cost of the 10 kilograms of material K is less than $40.
3x+5y < 40
x+y =10
x, y can take various values. Not sufficient

Combining both, nothing helps as y could be 5,6,7,8,9. Hence E

3:Lets summarize/simplify the information given in the question first.

Total Revenue = 25a + 15c
a + c = 500

Statement 1: Total Revenue = 10,500

a + c = 500
25a + 15c = 10500

2 equations and 2 variables. Solve for a and c. SUFFICIENT.

Statement 2: Average price per ticket = 21

Average price = Total Revenue/Total Number of People
21 = Total Revenue/500
Total Revenue = 10500

Same as Statement 1. Hence, SUFFICIENT.

Answer: D

4:an=a(n-4) or an= an-(4)
if an= a(n-4) then answer most humbly and respectfully would be 74 .(B)


5:D. (36+x)/6=median

If x=3 then median is 6.5
(36+3)/6=6.5 the mean=median
If x=7 then median is 7
(36+7)/6=43/6 the mean does not equal to the median
If x=12 then median is 8
(36+12)/6=8 the mean=the median

回答时间:2010-01-19 11:53:32 回答者:zsk_koo [知识堂达人]

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