Re: [計量] 請教幾題計量題目

看板GRE (GRE入學考試)作者cassine (Savannah)時間15年前 (2010/06/29 20:05)推噓3(3推 0噓 4→)

留言7則, 3人參與討論串2/2 (看更多)

※ 引述《cgcluck (Never give up!)》之銘言： : 麻煩板上數學高手解答，謝謝。 : 1.In a nationwide poll, N people were interviewed. If 1/4 of them answered : "yes" to question 1, and of those, 1/3 answered "yes" to question 2, which : of the following expressions represents the number if people interviewed : who did not answer "yes" to both questions? : The answer is 11N/12. 全國民調中，有 1/4的受訪者在第一個問題回答了「是」，而這些第一題答是「的」之中，又有 1/3在第二題答了「是」，問不是兩題都答「是」的人有多少？ N * ( 1 - 1/4 * 1/3 ) = 11N/12 : 2.The market value of a certain machine decreased by 30 percent of its : purchase price each year. If the machine was purchased in 1982 for its : market value of $8000, what was its market value two years later? : The answer is $3200. 機器的市場價值每年減少購買價的 30%，如果購買價是8000，問兩年後殘值多少？ 8000 * ( 1 - 2 * 30% ) = 3200 : 3.A fair die of six faces is tossed three times repeatedly. If the sum of the : number of dots from the first two times is equal to the number of dots from : third time, then what is the probability that least one of the three : successive tosses will get 2 dots? : The answer is 8/15. 一個公平的骰子連續丟三次，前兩次的點數和是第三次的點數，問至少有一次擲出點數為 2的機率為何。這題直接窮舉比較快 (1,1,2),(1,2,3),(2,1,3),(1,3,4),(3,1,4),(1,4,5),(4,1,5),(1,5,6),(5,1,6) (2,2,4),(2,3,5),(3,2,5),(2,4,6),(4,2,6) 8/15 : 以下這題題目我看不懂 : 4.Column A: The number that is as much greater than 63 as it is less than 101 : Column B: 84 : The answer is (B). 一個數字，比63大的量恰好等於比 101小的量，所以就是63和 101的平均數82。 -- ○ ____ _ _ _ _ ____ _ _ ____ _____ ____ 。 ★(_ _)( \( )( \/ )( ___)( \( )(_ _)( _ )( _ \ ｏ _)(_ ) ( \ / )__) ) ( )( )(_)( ) / ● ‧ (____)(_)\_) \/ (____)(_)\_) (__) (_____)(_)\_) ★ ｏ -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 218.166.182.250