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题目： Before a certain tire is used, 40 percent of its total weight consists of tread. If during a lifetime of use, 50 percent, by weight, of the tire's tread is lost and no other parts of the tire is lost, what per cent of the tire's total remaining weight consists of the remaining tread?

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题目： If $${x}^{2}-{y}={w}$$, what is the value of x?(1) w + y = 4(2) y = 1

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题目： For each of the years 2000,2003,2006, and 2009, the graph shows the carbon dioxide emissions produced by the consumption of petroleum for 9 countries. Emissions are measured in millions of metric tons of carbon dioxide, where 1 million = $$10^6$$.From each drop-down menu, select the option that creates the most accurate statement based on the information provided.Median carbon dioxide emissions for the 9 countries increased by [s[0]] million metric tons 2000 to 2009.In 2006,the range of carbon dioxide emissions for the 9 countries was approximately [s[1]] million metric tons.

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题目： If $$\sqrt x=25$$, then $$x^3-x^2=$$

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题目： If P, Q, and R are three distinct points, do line segments PQ and PR have the same length?(1)P is the midpoint of line segment QR.(2)Q and R lie on the same circle with center P.

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题目： Lists S and T consist of the same number of positive integers. Is the median of the integers in S greater than the average (arithmetic mean) of the integers in T?(1) The integers in S are consecutive even integers, and the integers in T are consecutive odd integers.(2) The sum of the integers in S is greater than the sum of the integers in T.

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题目： How much is 20 percent of a certain number?(1)10 percent of the number is 5.(2)40 percent of twice the number is 40.

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题目： Among a group of 2,500 people, 35 percent invest in municipal bonds, 18 percent invest in oil stocks, and 7 percent invest in both municipal bonds and oil stocks. If 1 person is to be randomly selected from the 2,500 people, what is the probability that the person selected will be one who invests in municipal bonds but NOT in oil stocks?

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题目： The average (arithmetic mean) of the 5 positive integers k, m, r, s, and t is 16, and k < m < r < s < t. If t is 40, what is the greatest possible value of the median of the 5 integers?

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题目： A certain liquid leaks out of a container at the rate of k liters for every x hours. If the liquid costs $6 per liter, what is the cost, in dollars, of the amount of the liquid that will leak out in y hours?

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题目： If the sequence $${x}_{1}$$, $${x}_{2}$$, $${x}_{3}$$, ..., $${x}_{n}$$, ... is such that $${x}_{1}={3}$$ and $${x}_{n+1}={2}{x}_{n}-{1}$$ for $$n\ge 1$$, then $${x}_{20}-{x}_{19}=$$

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题目： Yesterday each of the 35 members of a certain task force spent some time working on project P. The graph shows the number of hours and the number of members who spent that number of hours working on project P yesterday. What was the median number of hours that the members of the task force spent working on project P yesterday?

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题目： What is the greatest common factor of the positive integers j and k?(1)k = j + 1(2)jk is divisible by 5.

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题目： A circular mat with diameter 20 inches is placed on a square tabletop, each of whose sides is 24 inches long. Which of the following is closest to the fraction of the tabletop covered by the mat?

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题目： If n is an integer and 2 < n < 6, what is the value of n?(1)n is a factor of 15.(2)n is a factor of 21.