三道GWD的数学题~

yanjunma

1、The sides of a square region, measured to the nearest centimeters, are 6 centimeters long.  The least possible value of the actual area of the square region is

 

A.    36.00 sq cm

B.     35.00 sq cm

C.     33.75 sq cm

D.    30.25 sq cm

E.     25.00 sq cm

答案给的D

2、one kilogram of a certain coffee blend consists of x kilogram of type I coffee and y kilogram of type II coffee.  The cost of the blend is C dollars per kilogram, where C = 6.5x + 8.5y.  Is x < 0.8?

(1)     y > 0.15

(2)     C ≥ 7.30

                  

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.

B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.

C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.

D. EACH statement ALONE is sufficient.

E. Statements (1) and (2) TOGETHER are NOT sufficient.

答案B

3、

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

答案C

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

答案C

1、3题 没大看懂，nn们帮忙讲一下吧~ 

经常考试

1. 量某正方形的边长，取整到最接近的厘米是6厘米，问最小可能的面积

最小可能的边长是5.5， 再小就会取整到5厘米了，当然5.5实际是临界，不过就不管那么多了

所以5.5*5.5=D

2. x+y=1 所以 C=6.5x+8.5(1-x) 与 （2） 联立得x <= .6， 所以 x 必小于.8

3. S和R两种尺度是线性关系， 说明 S=Ra +b, 带入两组S和R值， 得 a=5/3 b=20, 然后 R=100 时 S=48

yanjunma

哦，神奇呀，谢谢~