国外英语考试《SAT Level 1》试题（网友回忆版）一
一、数及其运算
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1.
Two iced lattes cost $5.How much does it cost for seven iced lattes?
参考答案C
解析Just think: $5 for 2 iced lattes is $2.50 for 1.7 × $2.50 = $17.50.Or you can write a proportion.
2C = 35 
C = $17.50
2C = 35 C = $17.50
2.
Which of the following expressions represents the phrase “3 less than 2 times x”?
参考答案D
解析The phrase “3 less than 2 times x” means 2x minus 3 or 2x-3.
3.
In a classroom of 25 students, 10 of the students are females.What is the ratio of males to females in the classroom?
参考答案E
解析Because there are a total of 25 students, including 10 females, there must be 25 - 10 = 15 males.So the ratio of males to females is
.
.
4.
The sum of two numbers is 10 and the difference of the two numbers is 4.Which is the smaller of the two numbers?
参考答案A
解析Choices C (6) D (7) and E (8) cannot be the smallest number in a pair of numbers with a sum of 10.Choice B (4) cannot be correct because 4+6 = 10 but 6 - 4 is not 4.That leaves choice A (3).3+7 = 10, 7-3=4.
5.
When 3 times a number n is increased by 7, the result is at most 4 times the number decreased by 1.Which of the following expressions represents the sentence above?
参考答案A
解析The expression "at most" in the given sentence means less than or equal to.When 3 times a number n is increased by 7 (= 3n+7), the result is at most (≤) 4 times the number decreased by 1(= 4n-1).Hence, 3n+7≤4n-1.
6.
The sum of n consecutive integers is 11.If the least of these integers is -10, what is the value of n?
参考答案E
解析If the sum of n consecutive integers starting with -10 is 11, then the consecutive integers must range from -10 to +11, inclusive, so that number-pair opposites from -10 to +10 cancel each other.Including 0, there are 22 integers in this interval.
7.
If four pens cost $1.96, what is the greatest number of pens that can be purchased for $7.68?
参考答案C
解析If 4 pens cost $1.96, the cost of 1 pen is $1.96/4 = $0.49.The greatest number of pens that can be purchased for $7.68 is the greatest integer that is equal to or less than $7.68/$0.49.Since $7.68$0.49 = 15.67, the greatest number of pens that can be purchased is 15.
8.
Half the difference of two positive numbers is 10.If the smaller of the two numbers is 3, what is the sum of the two numbers?
参考答案A
解析If half the difference of two positive numbers is 10, then the difference of the two positive numbers is 20.If the smaller of the two numbers is 3, then the other positive number must be 23 since 23 - 3 = 20.Hence, the sum of the two numbers is 3+23 or 26.
9.
Which of the following is NOT an irrational number?
- A.
- B.
- C.e
- D.1.666...
- E.
参考答案D
解析Irrational numbers are no terminating and nonrepeating.1.666...is not irrational, since it is a repeating decimal.
10.
In a given high school, 60 percent of the teachers reported an annual salary greater than or equal to $50,000 a year.Which of the following must be greater than or equal to $50,000?
参考答案B
解析Since more than half of the teachers have salaries greater than or equal to $50,000, the median (middle value) salary must also be above $50,000.You do not know enough information to determine the mean and mode.
11.
p
q is defined as Pq/pq for all positive real numbers.Which of the following is equivalent to p/2?
q is defined as Pq/pq for all positive real numbers.Which of the following is equivalent to p/2?- A.p1
- B.pp
- C.p1/2
- D.1q
- E.p2
参考答案E
解析p2 = p2/p(2)
=P/2
2 = p2/p(2)=P/2
12.
The population of a bacteria culture doubles in number every 12 minutes.The ratio of the number of bacteria at the end of 1 hour to the number of bacteria at the beginning of that hour is
参考答案C
解析Let p represent the initial population of bacteria.After 12 minutes the population is 2p, after 24 minutes it is 4p, after 36 minutes it is 8p, after 48 minutes it is 16p, and after 60 minutes or 1 hour the population is 32p.Since 32p/p = 32/1, the ratio of the number of bacteria at the end of 1 hour to the number of bacteria at the beginning of that hour is 32 : 1.
13.
In a certain college, the ratio of mathematics majors to English majors is 3: 8.If in the following school year the number of mathematics majors increases 20% and the number of English majors decreases15%, what is the new ratio of mathematics majors to English majors?
参考答案C
解析Since the ratio of mathematics majors to English majors is given as 3: 8, suppose there are 30 mathematics majors and 80 English majors.If the number of mathematics majors increases 20%, then the new number of mathematics majors is 30+ (20%×30) = 30+6 = 36.If the number of English majors decreases 15%, then the new number of English majors is 80 - (15%×80) = 80 - 12 = 68.The new ratio of mathematics majors to English majors 36/68 = 9/17 or 9:17.
14.
30% of 150 equals 4.5% of ______.
参考答案D
解析30% of 150 = 0.30×150 = 45.Answer the question "4.5% of what number is45?" by solving the equation 0.045n =45.Since 0.045n = 45, n = 45/0.045 = 1000.
15.
What are three consecutive even integers whose sum is 48?
参考答案E
解析Let x = the first even integer, x + 2 = the second even integer, and x + 4 = the third.x+x+2+x+4=48, 3x+6=48, x=14.If 14 is the first even integer, 16 and 18 are the other two.
16.
The cost to rent a DVD is $4.50 for the first five days, with a $2.50 late fee for each succeeding day.Which of the following represents the cost of renting the DVD for d days if d is greater than 5?
参考答案B
解析Since d > 5, the cost is $4.50 for the first5 days and $2.50 for the remaining d-5 days.The cost is 4.50 + 2.50(d-5).
17.
The price of a stock falls 25%.By what percent of the new price must the stock price rise in order to reach its original value?
参考答案C
解析Suppose the original price of the stock was $100.If the price falls 25%, the new price of the stock is 0.75 × $100 = $75.To reach its original value, the price of the stock must rise $25, which is 1/3 or 33(1/3)% of its $75 price.
18.
A recipe for 4 servings requires salt and pepper to be added in the ratio of 2:3.If the recipe is adjusted from 4 to 8 servings, what is the ratio of the salt and pepper that must now be added?
参考答案C
解析When the recipe is adjusted from 4 to 8 servings, the amounts of salt and pepper are each doubled, so the ratio of 2: 3 remains the same.
19.
The regular price of software at a computer superstore is 12% off the retail price.During an annual sale, the same software is 25% off the regular price.If the retail price is p, which expression represents the sale price?
参考答案E
解析Since the regular price of software is 12% off the retail price p, the regular price of the software can be expressed as 0.88p.During an annual sale, the same software is 25% off the regular price, so the sale price is 0.75×0.88p = 0.66p.
20.
1/2 percent of 50 percent of 1,000 is ______.
参考答案A
解析1/2% of 50% of
21.
By the end of the school year, Terry had passed 80% of his science tests.If Terry failed 4 science tests, how many science tests did Terry pass?
参考答案C
解析Since Terry passed 80% of his science tests; he failed 20% or 1/5 of the tests taken.Terry failed 4 science tests, so 4 represents 1/5 of the total number of science tests.Hence, Terry took 5 ×4 or 20 science tests.Since he failed 4 tests, he passed 20-4 or 16 science tests.
22.
If 1/8 of a number is 9, what is 75% of the same number?
参考答案C
解析If 1/8 of a number is 9, then 8/8 or the whole number is 8 x 9 or 72.Hence, 75% of the same number is 0.75 × 72 = 54.
23.
During a basketball game Maria scored all of her points either from a two-point basket or a three-point basket.If she scored 15 points, which of the following could be the number of three-point baskets that Maria scored?
参考答案D
解析A.NO 8×3 = 24.She only scored 15 points so she could not have made eight three-pointers.
24.
Two times a number k is decreased by 1.If the cube root of that result is -2, then k = ______.
参考答案B
解析
, then 2k-1=(-2)3=-82k=-7, so k=-7/2=-3.5.
, then 2k-1=(-2)3=-82k=-7, so k=-7/2=-3.5.
25.
If 4x-y = 6z + w, then what does the expression 12-4x + y equal in terms of z and w?
参考答案E
解析12-4x+y=12-(4x-y)=12-(6z+w)=12-6z-w