- AB is the iameter of the circle. If AF=BF= 3√2,an AC=5, what is the area of square BCDE?
答案:11
解析:题干求正方形BCDE的面积,根据AF=BF=3 ,三角形ABF为直角三角形,得出AB=6。根据AC=5,三角形ABC为直角三角形,得出BC²=AB²-AC²=6²-5²=11。正方形BCDE的面积=BC²=11
- If the areas of the 4 squares are 50, 32, 18 an 12, what is the ratio of the small shae portion to the area of the large shae portion?(Note: Figure not rawn to scale)
A. 1:8
B. 1:6
C. 1:4
D. 1:3
E. 1:1
答案:D
解析:题干问小的黑色阴影面积/大的黑色阴影面积等于多少。小的黑色阴影面积=18-12=6,大的黑色阴影面积=50-32=18,所以小的黑色阴影面积/大的黑色阴影面积=6⁄18=1:3
- X = sum of the first 31 positive o integers
Y = sum of the first 30 positive even integers
Column A:X - Y
Column B:30
A. The quantity in Column A is greater
B. The quantity in Column B is greater
C. The two quantities are equal
D. The relationship cannot be etermine from the information given
答案:B
解析:已知公式,和=[(首项+末项)*项数]/2. 项数= [(末项-首项)/公差]+1
X=1+3+5+7+…+31=(1+31)*16⁄2=256
Y=2+4+6+8+…+30=(2+30)*15⁄2=240
所以X-Y=256-240=16. 比30小,所以选B.
- In a group of 45 chilren, 60 percent of the chilren are boys, an 60 percent of the chilren are left-hane.
Column A:Number of boys who are left-hane
Column B:8
A. The quantity in Column A is greater
B. The quantity in Column B is greater
C. The two quantities are equal
D. The relationship cannot be etermine from the information given
答案:A
解析:男孩的数量为45*60%=27, 用左手的人所占的百分比为60%, 所以用左手的男孩为27*60%=16.2. 而B是8. 所以A更大,所以选A.
- If a truck is traveling at a constant rate of 90kilometers per hour, how many secons will it take the truck to travel a istance of 600 meters? (1 kilometer = 1000 meters)
A. 18
B. 24
C. 30
D. 36
E. 48
答案: B 解析:
题干时速90公里的卡车需要多少秒通过600米的距离。首先换算时速90公里,90,000米/(60*60)秒=25米/秒,所以时间=距离/速度=600⁄25=24秒。
两个连续的整数数列R和T,其中R的中位数等于T的最小数,求两个数列合并后会有多少个不重复的整数。因为R的中卫数等于T的最小数,且R一共有15个数字,因此从R的第八个整数开始往后的一共8个整数将和T中的前8个整数重复,所以两者合并后不重复整数数量应该是15+21-8=28个,所以选C。