: 1.If the slope of line l is 3, and point (k,5) is on the line.
: Quantity A: K
: Quantity B: 2
D
點斜式,點愛在哪就在哪,斜率愛多大就多大
: 2.What is the greatest prime factor of 3^100-3^97?
(3^3 -1)3^97 = 26*3^97 = 2*13*(3^97)
答案:13
: 3.Companies C1 and C2 are among 18 companies, if 4 companies are selected from
: all these 18 companies, how many selections of 4 companies including both C1
: and C2? (數字填空題)
C16取2=120 (就從另外16家公司選兩家出來陪C1跟C2)
: 4.The lengths of two sides of a triangle are 5 and 12, which of following
: numbers could be the length of the other side?(不定項選擇題)
: A. 3 B. 9 C. 10 D. 12
比(12+5)小 比(12-5)大 都可以
所以選 BCD
: 5.If p=r^n,r is a prime number,and n is a positive integer,then define
: p▲=rn,for example,25=5^2, then 25▲=5*2=10. what is value of 32▲?
32=2^5
答案2*5=10
: 6.A物品售出後盈利25%,B物品售出後虧了25%,最終售價都是2100,求A、B兩種種物品起
: 始價格的和比4000多多少?
買進價格分別為a跟b
1.25a=2100, a=2100*0.8
0.75b=2100, b=2100*(4/3)
a+b=2100*(0.8+1.333) > 4000
注意:看清楚營利跟虧錢的"基數"是不是買進價格(成本)
: 7.If the standard deviation of a, b, c, d is 1, what is the standard deviation
: of a+1, b+1, c+1, d+1?
資料全體一同平移==>標準差不改變
: 8.一個班級共計25人,其中A所得到的分數比班級的平均分average多6.2,經過加試後,A
: 又多獲得10分,其他同學成績不變,求A的新成績比班級的新的平均分多多少?
10/25 = 0.4
此人又多拿10分,拉高了全班平均0.4分
所以把個人成績與班平均之間的差距又加大了10-0.4=9.6
所以此人的新成績減去新的班平均為6.2+9.6=15.8
: 9.在一個圓內有個P點,圓的周長circumference是12。
: Quantity A: P點距離圓周最長的距離和最短距離的和
: Quantity B: 4
P點距離圓周最長距離 + P點距離圓周最短距離 = 直徑
周長12,所以直徑=12除以拍==>比4小
答案B
: 10.What is the ratio of furniture to items in all shaded area?(其他部分也有具體
: 的百分數)
沒圖不解
: 11.If f(x)=x^2+2x, g(x)=x-2, what is the least value of x when f(x)=g(x)?
: (數字填空題)
f(x) = g(x) 求解
x^2 + 2x = x-2 ==> x^2 + x + 2 = 0 ==> 無實數解
數字又背錯了嗎?
: 12.What is value of r percent of s percent of 200?
: A. rs/100 B. rs/50 C. rs/20 D. rs E. 50rs
看到percent就寫個分母100,of就是乘,what 就是問號,BE動詞就是=
? = (r/100)*(s/100)*200
==>答案B
: 13.In a certain sequence, the first term is x, and each term is -2 times than
: the preceding term, what is the sum of the first five terms?
是漏字還是多字呢?
-2 times than 這個用法怪怪的耶
3 times more than <