GWD10

syf1985085

1

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 of 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

 

A certain quantity is measured on two different scales, the R-scale and the S-scale, that are related linearly.  Measurements on the R-scale of 6 and 24 correspond to measurements on the S-scale of 30 and 60, respectively.  What measurement on the R-scale corresponds to a measurement of 100 on the S-scale?

 

A.     20

B.     36

C.     48

D.     60

E.      84

 

 

At a garage sale, all of the prices of the items sold were different.  If the price of a radio sold at the garage sale was both the 15th highest price and the 20th lowest price among the prices of the items sold, how many items were sold at the garage sale?

 

A.     33

B.     34

C.     35

D.     36

E.      37

 

 

In 1994, Kenneth’s annual salary was 30 percent higher than it was in 1993.  In 1995, Kenneth’s annual salary was reduced to 104 percent of his 1993 annual salary.  Kenneth’s 1995 annual salary was what percent less than his 1994 annual salary?

 

A.      16%

B.       20%

C.      24%

D.      26%

E.       28%

 

 

 

以上几题不是很理解,请牛牛指教.

不知道为什么,每次做GWD的数学总是差不多要错几题,无法做到全对,似乎是个瓶颈,不知道要怎么突破......

 

 

 

QiangbaiGirl

按照题目顺序:

Sequence Letter problem:  P5(10 )/ P4(10) = 10*9*8*7*6/10*9*8*7 = 6/1 (Permutation problem)

Scale probelm: Let y=ax+b, then you get two equations 1). 6a+b=30.  2)24a+b=60 . then you can get a=5/3, b=20. Then, you can work out the equation 3y=5x+60. Let y=100, then x=48.

Garage Sales: 15+20-1 = 34

Kenneth Salary: From the question, you can get two equations: 1). A(1994)=1.3A(1993)   2). A(1995)=1.04A(1993). Then A(1994)/1.3 = A(1995)/1.04. You can get A(1995)/A(1994)=1.04/1.3=0.8, therefore, A(1995)=0.80A(1994). The answer is 1-80%=20%.

I will have my exam on April 1. However, work quite little on it! Good luck!

syf1985085

等于３４的那题，还不是太懂，有点不明白题目意思．．．

QiangbaiGirl

Sorry, i could only type in English in this computer.
You can use a simple model to work out the theory. Assume one book is the 6th of the left and the 3rd from the right. count it by yourself. Then you could easily work out it is 6+3-1. So, just apply this equation in the questions.

dianecarton

那俺来用汉语讲那道题。卖货，一台收音机卖的价钱在价目单上正数第15，倒数第20，问一共卖了多少货。20+15-1=34 因为当把收音机排名正数倒数提到两次的时候，重复了一次要减去。