问几题数学，GWD上的，望好心人解答~

茶色的秋天

The sides of a square region, measured to the nearest centimeter, 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
                                     Answer：
我选D，答案选C。不懂

茶色的秋天

If the average (arithmetic mean) of the assessed values of x houses is $212,000 and the average of the assessed values of y other houses is $194,000, what is the average of the assessed values of the x+y houses?
(1)    x+y=36
(2)    x=2y
                                                            Answer：
我选B。答案是C，我觉得B对。

茶色的秋天

At a fruit stand yesterday, the price of each apple was $0.10 more than the price of each orange. What was the total revenue from the sale of oranges at the fruit stand yesterday?
(1) The number of oranges sold at the fruit stand yesterday was 5 more than the number of apples.
  (2) The total revenue from the sale of apples at the fruit stand yesterday was $15.00.
                            Answer:
我选E，答案是C。不解。

茶色的秋天

If X>1 and Y>1, is X<Y?
(1) X^2/(XY+X)<1
  (2)XY/Y2-Y<1
                                                           Answer:
答案是E，我选的是B

茶色的秋天

Last year in a group of 30 businesses, 21 reported a net profit and 15 had investments in foreign markets. How many of the businesses did not report a net profit nor invest in foreign markets last year?
(1) Last year 12 of the 30 businesses reported a net profit and had investments in foreign markets.
(2) Last year 24 of the 30 businesses eported a net profit or invested in
                                                   Answer:
答案否定了1，所以选B，而我选的是D。

你家兜爷

measured to the nearest centimeter 这个是说在四舍五入还是？我算出来31.36.。。求解！

茶色的秋天

在此谢过

yangjingkey

1.感觉这题不严密，按四舍五入来说，边长肯定要大于5.50，那么总面积必然大于30.25，在大于30.25的基础上取最小值咯。。。另外楼上的算出31.36的也不严密，因为边长只需要大于5.50即可 不一定要达到5.60

低龄儿童小蘑菇

the least possible value 是指可能的最小值，还是最不可能的值？

茶色的秋天

取5.5为什么不行呢，这不就可以四舍五入为6了么？