A list contains n consecutive integers. The least integer on the list is −8, and the sum of the integers is 0. What is the value of n?
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In the figure above, what is the degree measure of angle A?
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One of the roots of the equation 2x2 − 9x – 18 = 0 is 6. What is the other root?
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x is a real number greater than 30.
y is a real number less than −40
Quantity A | Quantity B |
y − x | x-y |
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(B) Pick numbers, say 40 for x and −50 for y. Then (A) is −50 − 40 = −90, and (B) is 40 − (−50) = 40 + 50 = 90. So (B) is greater. Quantity (B) will always be greater because it will be positive in value (since the double negatives cancel to make a positive), while Quantity (A) will always be negative.
The probability that independent events C and D will both occur is 0.11.
Quantity A | Quantity B |
The probability that event C will occur | 0.09 |
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(A) The probability of any event is between 0 and 1, inclusive; that is, 0 ≤ p ≤ 1, for any probability, p. The probability of two independent events both occurring is the product of their individual probabilities. If the probability of Event C occurring were as low as .09, the value in column (B), then the probability of both events occurring would be less than or equal to .09, since .09 times a number from 0 through 1 would be at most .09. But the given probability of both events occurring is .11, which is greater than .09, so the probability of Event C occurring cannot be as low as .09, and therefore it must be greater than .09, and (A) is correct.
Mary paid $201 for a stereo that was marked at 25% off the original list price.
Quantity A | Quantity B |
The amount Nan paid for the same stereo marked at 15% off the original list price | $227 |
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(A) Let p = the full price, before any discounts. Then Mary, who received 25% marked off the price, paid p – .25p = .75p. Since she also paid $201, we know .75p = 201. Divide by .75 to obtain 1p = $268. Nan received a 15% discount, so she paid 1p – .15p = .85p, which is .85 × 268 = $227.80, a little more than $227, so (A) is correct
If p and m are odd integers, then which of the following must be an even integer?
Indicate all that apply.
A. p × m
B. 3p – 2m
C. 2(p + 2m)
D. p + m
E. 3(3p + 5m)
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(C, D, E) Easiest is to pick numbers for the two odds, say p = 3, and m = 5. Then (A) is pm = 15, not an even number, and (B) is 3(3) – 2(5) = –1, also not even, so (A) and (B) are both incorrect. (C) is always even by definition, because it is written as 2 times another integer. Because 3 + 5 = 8, (D) is correct. 8 is even, and, in general, the sum of two odds is even. (E) is correct, because the value of the inner parentheses is even (since it is the sum of two odd numbers), and an even times any integer is even. Here, for example, (3 × 3 + 5 × 5) = 9 + 25 = 34. Answer is (C), (D), and (E).
The lengths of three sides of a triangle are 12, 17, and x. The perimeter of the triangle could be which of the following?
Indicate all that apply.
A. 28
B. 34
C. 40
D. 57
E. 60
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(C, D) The triangle inequality states that in a triangle, the sum of any two of the side lengths is always greater than the length of any one. Equivalently, any one side length in a triangle must be less than the sum of the other two, but greater than the difference of the other two side lengths. Here, 17 – 12 < x < 17 + 12, or 5 < x < 29. Then the sum of the triangle’s three side length, its perimeter, will be greater than 5 + 12 + 17 but less than 29 + 12 + 17. This means 34 < perimeter < 58. Choices (C) and (D) satisfy this.
In a given month, a restaurant spends between 55% and 70% of its revenue on food and supplies, and between 23% and 28% of its revenue on staff salaries. The remaining revenue is the restaurant’s net profit. If the restaurant earned $80,000 in revenue one month, which of the following could have been its net profit?
Indicate all that apply.
A. $1,000
B. $1,700
C. $10,000
D. $17,000
E. $18,000
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(B, C, D) The restaurant will spend more than 55 + 23 = 78% of its revenue but less than 70 + 28 = 98% of its revenue on food, supplies, and staff salaries combined. Then its remaining net profit, after these expenses are subtracted from revenue, will be between 2% and 22% of revenue, because 100 – 78 = 22, and 100 – 98 = 2. Then for a revenue of $80,000, the profit, p, will satisfy .02 × 80,000 < p < .22 × 80,000, which implies 1600 < p < 17600. (B), (C), and (D) satisfy this.
Questions are based on the following chart, which shows how Ann spent her income of $4,080 one month.
Ann spent twice as much on expenses as on savings. If she spent an equal amount on food plus rent as on expenses plus savings, how much did she spend on expenses?
$
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Questions are based on the following chart, which shows how Ann spent her income of $4,080 one month.
Ann’s rent represents 25% of her total spending. If her rent decreases by $244.80, and she uses this money to add to her savings, what percent of her total spending will then be used for rent?
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If six books cost a total of $29.10, then 16 books at the same price per book would cost how much?
$
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If 69 – 11x = 3x – 99, then what is the value of x?
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A special language is invented with 12 consonants and five vowels. All words in the language contain exactly four letters. All words begin and end with a consonant and have two vowels in between. How many possible words in the language contain four different letters?
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(2,640) Draw out four blanks to represent the four places in the word to be filled: ________ ________ ________ ________. In each blank, write the number of different ways that particular place can be filled. The total number of combinations will then equal the product of the numbers in the blanks. There are 12 consonants and five vowels in the language. Words fit the CVVC pattern, so we might expect the total number of possible words to equal 12 × 5 × 5 × 12. But since we are looking for words with no repeated letters, the number of possibilities for the second vowel and for the second consonant are each reduced by 1, so the answer becomes 12 × 5 × 4 × 11 = 2,640 possible words with four different letters.
Questions are based on the following table, which shows trends in sales at four companies over a 2–year period.
If the total sales for Company D in the year 2009 were $66,000, what were the sales at Company D in the year 2011, rounded to the nearest dollar?
$
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($78,104) When Company D’s value decreased by 3%, it retained 97% of its value of $66,000, which is .97 × 66,000 = $64,020. In the following year, it increased in value by 22% of this, or .22 × $64,020 = $14,084.40. When this increase is added to 64,020, the final value becomes $78104.4, which rounds to $78,104.
*A nice shortcut is to think of the final value as 1.22(.97(66,000)), which is entered on the calculator as 1.22 × .97 × 66,000 = 78,104.4 ≈ 78,104. In this approach, we obtain 1.22 mentally by thinking of (value + 22% of value) as 1V + .22V = 1.22V. Similarly, value minus 3% of value is 1V – .03V = .97V, justifying the shortcut.
Questions are based on the following table, which shows trends in sales at four companies over a 2–year period.
Which company’s total sales increased by the most dollars over the 2-year period?
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(E) We are informed of the percent change in the companies’ total sales, but we have no information on the actual sales amounts in dollars. A small percentage of a high sales total could be greater than a larger percentage of a low sales total. Therefore, (E), there is not enough information to determine.
Questions are based on the following table, which shows trends in sales at four companies over a 2–year period.
Which of the following statements must be true?
Indicate all that apply.
A. Company A’s total sales decreased over the 2-year period from 2009 to 2011.
B. Company B’s total sales increased by a higher percentage over the 2-year period than any of the other company’s.
C. At Company C, the ratio of total sales in 2011 to total sales in 2009 was 112:100, or 28:25.
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(A, B) For (A), it is easiest to imagine that the company started with sales of $100. After a 10% increase, it had sales of 100 + 10 = $110. When the company next experienced a 10% decrease in sales, it lost .10 × 110 = $11 in sales, so it had only $110 – 11 = $99 in sales. (Or .9 × 110 = $99, as in 16* above.) This makes (A) correct, because 99 < 100, corresponding to a decrease in sales from the starting value. To compute Company B’s change in sales for the 2-year period, multiply 1.12 by 1.13 to represent the 12% increase “on top of” a 13% increase (again, see 16* above). This yields 1.12 × 1.13 ≈ 1.266, or about a 26.6% increase for the 2-year period. Inspection of the other numbers shows that none of the other companies increased by as much, so (B) is correct. You can use the percent change figures to compute Company C’s total sales ratio for 2011 to 2009. Assume the figure is $100 in 2009. After a 17% increase, the sales will equal $117. However, to decrease this number, $117, by 5% is not to simply subtract 5 from 117, to obtain 112, and so the ratio will not equal 112:100, and (C) is not correct. Company C’s sales in 2011 in this example would equal .95 × 117 = 111.15, and so the proper ratio of sales between the two years would be 111.15:100. Answer is (A) and (B).
A company manufactures nails that are meant to be precisely 10 cm long. The company devalues nails that differ in length from 10 cm. The amount a nail is devalued, in cents, is given by the function \(D(x) = \sqrt{|x-6|}\) , where x represents the nail’s length in centimeters and D represents the amount of the devaluation in cents. How much is a nail measuring 9.91 cm devalued?
Cents
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The area of rectangular region ABCD is equal to the area of the isosceles trapezoid PQRS, with PS equal to QR. What is the length of segment \(\overline{QR}\) ?
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