[計量] 請教三題計量

看板GRE作者leetzuwen (蚊子)時間13年前 (2010/10/22 00:35)推噓8(8推 0噓 11→)

留言19則, 8人參與討論串1/1

1. Column A) Using all the prime numbers less than 10 how many 3-digit even numbers can be made if repetition is not allowed. Column B) Using all the prime numbers less than 7 how many 2-digit numbers can be made if repetition is not allowed. 答案是A 但是我算出來兩個是一樣的 2. Column A) There are 2 sections in a question paper. In the first section 3 questions have to be attempted out of 4 and the second section 4 questions have to be attempted out of 5. In the second section the first two questions are compulsory. How many choices can be made? Column B) There are 2 sections in a question paper. In the first section 3 questions have to be attempted out of 4 and the second section 4 questions have to be attempted out of 5.How many choices can be made? 答案是C Column A的題意是是指2個固定接著3個取2的意思嗎? 還是我誤會題意了? 3. Column A) two letters are followed by four digits(0-9). The letters are be taken from 5 letters of Eng alphabet without repetition, and the digits also not to be repeated. How many possible serial numbers? Column B) four letters are followed by two digits(0-9). The letters are be taken from 5 letters of Eng alphabet without repetition, and the digits also not to be repeated. How many possible serial numbers? 答案是C 可是怎麼看都不會一樣阿.... -- 我是在http://www.greguide.com的練習題做的不知道答案是不是有錯 QQ -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 114.37.133.211

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ron0908

10/22 00:44, , 1^F

10/22 00:44, 1^F

※ 編輯: leetzuwen 來自: 114.37.133.211 (10/22 00:45)

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youbet

10/22 00:45, , 2^F

10/22 00:45, 2^F

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leetzuwen

10/22 00:46, , 3^F