There are 3 boxes and 8 letter A to H.
a)When the letters are placed in a row, find the number of arragements if the letter A, B, C and D are separated from each other?
b)Find the number of ways in which 8 letters can be placed in the boxes if there is no restriction?
a答案:2880
b答案:6561
請問點做???
Thankyou~~~~
數學問題!!!
2007-09-18 3:50 am
回答 (1)
2007-09-19 12:59 am
✔ 最佳答案
1a) There are 5 ways to place the ABCD, namelyx_x_x_x_
x_x_x__x
x_x__x_x
x__x_x_x
b) For the ABCD, there are 4!=24 ways to place the letters.
c) For the other letters, there are also 4!=24 ways to place the letters
d) Total no. of arrangements =5x24X24=2880.
2a) Each letter can have three ways to place to as there are three boxes.
b) Total no. of ways to place the 8 letters=3x3x3x3x3x3x3x3=6561.
收錄日期: 2021-04-23 22:17:39
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