(D) $10 (E) $12
------------------------------------------------------------------------------------------------------------------------------------ 【答案】D 【思路】 3×8＝24
(24＋16)÷4＝10
------------------------------------------------------------------------------------------------------------------------------------ 54. 6787-!-item-!-187;#058&005232
An auction house charges a commission of 15 percent on the first $50,000 of the sale price of an item, plus 10 percent on the amount of the sale price in excess of $50,000. What was the sale price of a painting for which the auction house charged a total commission of $24,000 ? (A) $115,000 (B) $160,000 (C) $215,000 (D) $240,000 (E) $365,000
------------------------------------------------------------------------------------------------------------------------------------ 【答案】C 【思路】
plus 10 percent on the amount of the sale price in excess of $50,000 超過50000的部份收10%
設the amount of the sale price 為x
50000×15％＋(x-50000)×(10％)＝24000 X＝215000
------------------------------------------------------------------------------------------------------------------------------------ 55. 6892-!-item-!-187;#058&005291
Which of the following inequalities has a solution set that, when graphed on the number line, is a single line segment of finite length?
(A) X4 ≧ 1 (B) X3 ≦ 27 (C) X2 ≧ 16
(D) 2 ≦ |X| ≦ 5 (E) 2 ≦ 3X + 4 ≦ 6 56. 6998-!-item-!-187;#058&005424
A small water pump would take 2 hours to fill an empty tank. A larger pump would take 1/2 hour to fill the same tank. How many hours would it take both pumps, working at their respective constant rates, to fill the empty tank if they began pumping at the same time?
(A) 1/4 (B) 1/3 (C) 2/5 (D) 5/4 (E) 3/2 57. 7044-!-item-!-187;#058&005427 If n is a multiple of 5 and be a multiple of 25 ? (A) (B)
n??p2?q , where p and q are prime numbers, which of the following must rt
p2
q2 (C) pq
22(D) pq
(E)
p3q
------------------------------------------------------------------------------------------------------------------------------------ 【答案】D 【思路】
題目給的是n的質因式分解 因為n為5的乘數 那麼n的質因式中必定包含5這個因子 所以有兩種可能 p=5或q=5
如果p=5 q不一定 那麼n可以被25整除 因為這裡已經有兩個5的因子 但是如果q=5 p不一定 此時 只有增加一個質因子p 才能保證為25整除 [另解]
題目說:p^2q=5k
這邊就要先推論一下,有兩種可能情形: (1)p=5,k=pq (2)q=5,k=p^2
直接看答案D
(p^2)(q^2)=5kq (由題目推的) 再帶入剛剛的兩種情形 (1)5kq=5(pq)(q)=25q^2 (2)5kq=5(p^2)(5)=25p^2 所以只有
p2q2符合條件!
------------------------------------------------------------------------------------------------------------------------------------ 58. 7090-!-item-!-187;#058&005463
In the graduating class of a certain college, 48 percent of the students are male and 52 percent are female. In this class 40 percent of the male and 20 percent of the female students are 25 years old or older. If one student in the graduating class is randomly selected, approximately what is the probability that he or she will be less than 25 years old? (A) 0.90 (B) 0.70 (C) 0.45 (D) 0.30 (E) 0.25
------------------------------------------------------------------------------------------------------------------------------------ 【答案】B 【思路】
設the graduating class 共有x位學生
48x人 10052Female有x人
100Male 有
4048x＝0.192x
1001002052x=0.104x Female且25 years old or older有
100100(0.192x?0.104x)求少於25歲的人數比例，?0.296
xMale且25 years old or older有
1-0.296=0.704
------------------------------------------------------------------------------------------------------------------------------------
59. 7143-!-item-!-187;#058&005466
In the figure above, points P and Q lie on the circle with center O. What is the value of s ?
(A) 1/2 (B) 1 (C) √2 (D) √3 (E) √2/2 60. 7189-!-item-!-187;#058&005472
Rates for having a manuscript typed at a certain typing service are $5 per page for the first time a page is typed and $3 per page each time a page is revised. If a certain manuscript has 100 pages, of which 40 were revised only once, 10 were revised twice, and the rest required no revisions, what was the total cost of having the manuscript typed? (A) $430 (B) $620 (C) $650 (D) $680 (E) $770
------------------------------------------------------------------------------------------------------------------------------------ 【答案】D 【思路】
(100?5)?(40?3)?(10?2?3)?680
------------------------------------------------------------------------------------------------------------------------------------ 61. 7409-!-item-!-187;#058&005546
As shown in the figure above, a thin conveyor belt 15 feet long is drawn tightly around two circular wheels each 1 foot in diameter. What is the distance, in feet, between the centers of the two wheels?
(A) (15 -π ) / 2 (B) 5π/4 (C) 15 - 2π (D) 15 -π (E) 2π 62. 7564-!-item-!-187;#058&005577
Alice's take-home pay last year was the same each month, and she saved the same fraction of her
take-home pay each month. The total amount of money that she had saved at the end of the year was 3 times the amount of that portion of her monthly take-home pay that she did not save. If all the money that she saved last year was from her take-home pay, what fraction of her take-home pay did she save each month?
(A) 1/2 (B) 1/3 (C) 1/4
(D) 1/5 (E) 1/6 63. 7612-!-item-!-187;#058&005607
For which of the following functions is f(a + b) = f(a) + f(b) for all positive numbers a and b ?
(A) f(x) = x 2 (B) f(x) = x + 1 (C) f(x) = √x (D) f(x) = 2/x (E) f(x) = -3x 64. 7659-!-item-!-187;#058&005610
If in a certain population, people are born at an average rate of 9 people every 2 seconds and people die at an average rate of 3 people every 2 seconds, by approximately how many people does the population increase in 1 day? (A) 17,280 (B) 25,920 (C) 129,600 (D) 259,200 (E) 388,800
------------------------------------------------------------------------------------------------------------------------------------ 【答案】D 【思路】
born at an average rate of 9 people every 2 seconds且die at an average rate of 3 people every 2 seconds 得知人口每兩秒增加6個人
6?60?60?24?259200 2n2------------------------------------------------------------------------------------------------------------------------------------ 65. 7870-!-item-!-187;#058&005675 For how many integers n is 2?n? (A) None (B) One (C) Two (D) Three
(E) More than three
------------------------------------------------------------------------------------------------------------------------------------ 【答案】C 【思路】
2 and 4 兩個整數
------------------------------------------------------------------------------------------------------------------------------------ 66. 7916-!-item-!-187;#058&005701
The manager of a theater noted that for every 10 admission tickets sold, the theater sells 3 bags of popcorn at $2.25 each, 4 sodas at $1.50 each, and 2 candy bars at $1.00 each. To the nearest cent, what is the average (arithmetic mean) amount of these snack sales per ticket sold? (A) $1.48 (B) $1.58 (C) $1.60 (D) $1.64 (E) $1.70
------------------------------------------------------------------------------------------------------------------------------------ 【答案】A 【思路】
(3×2.25)＋(4×1.5)＋(2×1)=14.75 即10 admission tickets sold會有14.75的收入 14.75÷10=1.475
------------------------------------------------------------------------------------------------------------------------------------ 67. 7966-!-item-!-187;#058&005724
相关推荐：
loading