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Antworten 5678

 #2
avatar+26396 
+17

The numbers 1,2,3,4,5,6,7,8,9 are arranged in a list so that each number is either greater than all the numbers that come before it or is less than all the numbers that come before it. For example, 4,5,6,3,2,7,1,8,9 is one such list: notice that (for instance) the 6 is greater than all the numbers that come before it, and the 2 is less than all the numbers that come before it. How many such lists of the numbers 1,2,3,4,5,6,7,8,9 are possible? Be sure to include complete explanations with your answer, using complete sentences. Imagine you were going to show your solution to a classmate, and try to write your solution so that he or she could understand it without doing any extra work.

 

How many such lists of the numbers 1,2,3,4,5,6,7,8,9 are possible?

 

n=9

 

There are 2n1=291=28=256 lists possible.

 

See Pascal's Triangle: Sum in line n1=91=8

=(1+8+28+56+70+56+28+8+1)=28=256

 

Lists:

1. ( 1, 2, 3, 4, 5, 6, 7, 8, 9 ) (1 list start with 1)

 

2. ( 2, 1, 3, 4, 5, 6, 7, 8, 9 )
3. ( 2, 3, 1, 4, 5, 6, 7, 8, 9 )
4. ( 2, 3, 4, 1, 5, 6, 7, 8, 9 )
5. ( 2, 3, 4, 5, 1, 6, 7, 8, 9 )
6. ( 2, 3, 4, 5, 6, 1, 7, 8, 9 )
7. ( 2, 3, 4, 5, 6, 7, 1, 8, 9 )
8. ( 2, 3, 4, 5, 6, 7, 8, 1, 9 )
9. ( 2, 3, 4, 5, 6, 7, 8, 9, 1 ) (8 lists start with 2)

 

10. ( 3, 2, 1, 4, 5, 6, 7, 8, 9 )
11. ( 3, 2, 4, 1, 5, 6, 7, 8, 9 )
12. ( 3, 2, 4, 5, 1, 6, 7, 8, 9 )
13. ( 3, 2, 4, 5, 6, 1, 7, 8, 9 )
14. ( 3, 2, 4, 5, 6, 7, 1, 8, 9 )
15. ( 3, 2, 4, 5, 6, 7, 8, 1, 9 )
16. ( 3, 2, 4, 5, 6, 7, 8, 9, 1 )
17. ( 3, 4, 2, 1, 5, 6, 7, 8, 9 )
18. ( 3, 4, 2, 5, 1, 6, 7, 8, 9 )
19. ( 3, 4, 2, 5, 6, 1, 7, 8, 9 )
20. ( 3, 4, 2, 5, 6, 7, 1, 8, 9 )
21. ( 3, 4, 2, 5, 6, 7, 8, 1, 9 )
22. ( 3, 4, 2, 5, 6, 7, 8, 9, 1 )
23. ( 3, 4, 5, 2, 1, 6, 7, 8, 9 )
24. ( 3, 4, 5, 2, 6, 1, 7, 8, 9 )
25. ( 3, 4, 5, 2, 6, 7, 1, 8, 9 )
26. ( 3, 4, 5, 2, 6, 7, 8, 1, 9 )
27. ( 3, 4, 5, 2, 6, 7, 8, 9, 1 )
28. ( 3, 4, 5, 6, 2, 1, 7, 8, 9 )
29. ( 3, 4, 5, 6, 2, 7, 1, 8, 9 )
30. ( 3, 4, 5, 6, 2, 7, 8, 1, 9 )
31. ( 3, 4, 5, 6, 2, 7, 8, 9, 1 )
32. ( 3, 4, 5, 6, 7, 2, 1, 8, 9 )
33. ( 3, 4, 5, 6, 7, 2, 8, 1, 9 )
34. ( 3, 4, 5, 6, 7, 2, 8, 9, 1 )
35. ( 3, 4, 5, 6, 7, 8, 2, 1, 9 )
36. ( 3, 4, 5, 6, 7, 8, 2, 9, 1 )
37. ( 3, 4, 5, 6, 7, 8, 9, 2, 1 ) (28 lists start with 3)

 

38. ( 4, 3, 2, 1, 5, 6, 7, 8, 9 )
39. ( 4, 3, 2, 5, 1, 6, 7, 8, 9 )
40. ( 4, 3, 2, 5, 6, 1, 7, 8, 9 )
41. ( 4, 3, 2, 5, 6, 7, 1, 8, 9 )
42. ( 4, 3, 2, 5, 6, 7, 8, 1, 9 )
43. ( 4, 3, 2, 5, 6, 7, 8, 9, 1 )
44. ( 4, 3, 5, 2, 1, 6, 7, 8, 9 )
45. ( 4, 3, 5, 2, 6, 1, 7, 8, 9 )
46. ( 4, 3, 5, 2, 6, 7, 1, 8, 9 )
47. ( 4, 3, 5, 2, 6, 7, 8, 1, 9 )
48. ( 4, 3, 5, 2, 6, 7, 8, 9, 1 )
49. ( 4, 3, 5, 6, 2, 1, 7, 8, 9 )
50. ( 4, 3, 5, 6, 2, 7, 1, 8, 9 )
51. ( 4, 3, 5, 6, 2, 7, 8, 1, 9 )
52. ( 4, 3, 5, 6, 2, 7, 8, 9, 1 )
53. ( 4, 3, 5, 6, 7, 2, 1, 8, 9 )
54. ( 4, 3, 5, 6, 7, 2, 8, 1, 9 )
55. ( 4, 3, 5, 6, 7, 2, 8, 9, 1 )
56. ( 4, 3, 5, 6, 7, 8, 2, 1, 9 )
57. ( 4, 3, 5, 6, 7, 8, 2, 9, 1 )
58. ( 4, 3, 5, 6, 7, 8, 9, 2, 1 )
59. ( 4, 5, 3, 2, 1, 6, 7, 8, 9 )
60. ( 4, 5, 3, 2, 6, 1, 7, 8, 9 )
61. ( 4, 5, 3, 2, 6, 7, 1, 8, 9 )
62. ( 4, 5, 3, 2, 6, 7, 8, 1, 9 )
63. ( 4, 5, 3, 2, 6, 7, 8, 9, 1 )
64. ( 4, 5, 3, 6, 2, 1, 7, 8, 9 )
65. ( 4, 5, 3, 6, 2, 7, 1, 8, 9 )
66. ( 4, 5, 3, 6, 2, 7, 8, 1, 9 )
67. ( 4, 5, 3, 6, 2, 7, 8, 9, 1 )
68. ( 4, 5, 3, 6, 7, 2, 1, 8, 9 )
69. ( 4, 5, 3, 6, 7, 2, 8, 1, 9 )
70. ( 4, 5, 3, 6, 7, 2, 8, 9, 1 )
71. ( 4, 5, 3, 6, 7, 8, 2, 1, 9 )
72. ( 4, 5, 3, 6, 7, 8, 2, 9, 1 )
73. ( 4, 5, 3, 6, 7, 8, 9, 2, 1 )
74. ( 4, 5, 6, 3, 2, 1, 7, 8, 9 )
75. ( 4, 5, 6, 3, 2, 7, 1, 8, 9 )
76. ( 4, 5, 6, 3, 2, 7, 8, 1, 9 )
77. ( 4, 5, 6, 3, 2, 7, 8, 9, 1 )
78. ( 4, 5, 6, 3, 7, 2, 1, 8, 9 )
79. ( 4, 5, 6, 3, 7, 2, 8, 1, 9 )
80. ( 4, 5, 6, 3, 7, 2, 8, 9, 1 )
81. ( 4, 5, 6, 3, 7, 8, 2, 1, 9 )
82. ( 4, 5, 6, 3, 7, 8, 2, 9, 1 )
83. ( 4, 5, 6, 3, 7, 8, 9, 2, 1 )
84. ( 4, 5, 6, 7, 3, 2, 1, 8, 9 )
85. ( 4, 5, 6, 7, 3, 2, 8, 1, 9 )
86. ( 4, 5, 6, 7, 3, 2, 8, 9, 1 )
87. ( 4, 5, 6, 7, 3, 8, 2, 1, 9 )
88. ( 4, 5, 6, 7, 3, 8, 2, 9, 1 )
89. ( 4, 5, 6, 7, 3, 8, 9, 2, 1 )
90. ( 4, 5, 6, 7, 8, 3, 2, 1, 9 )
91. ( 4, 5, 6, 7, 8, 3, 2, 9, 1 )
92. ( 4, 5, 6, 7, 8, 3, 9, 2, 1 )
93. ( 4, 5, 6, 7, 8, 9, 3, 2, 1 ) (56 lists start with 4)

 

94. ( 5, 4, 3, 2, 1, 6, 7, 8, 9 )
95. ( 5, 4, 3, 2, 6, 1, 7, 8, 9 )
96. ( 5, 4, 3, 2, 6, 7, 1, 8, 9 )
97. ( 5, 4, 3, 2, 6, 7, 8, 1, 9 )
98. ( 5, 4, 3, 2, 6, 7, 8, 9, 1 )
99. ( 5, 4, 3, 6, 2, 1, 7, 8, 9 )
100. ( 5, 4, 3, 6, 2, 7, 1, 8, 9 )
101. ( 5, 4, 3, 6, 2, 7, 8, 1, 9 )
102. ( 5, 4, 3, 6, 2, 7, 8, 9, 1 )
103. ( 5, 4, 3, 6, 7, 2, 1, 8, 9 )
104. ( 5, 4, 3, 6, 7, 2, 8, 1, 9 )
105. ( 5, 4, 3, 6, 7, 2, 8, 9, 1 )
106. ( 5, 4, 3, 6, 7, 8, 2, 1, 9 )
107. ( 5, 4, 3, 6, 7, 8, 2, 9, 1 )
108. ( 5, 4, 3, 6, 7, 8, 9, 2, 1 )
109. ( 5, 4, 6, 3, 2, 1, 7, 8, 9 )
110. ( 5, 4, 6, 3, 2, 7, 1, 8, 9 )
111. ( 5, 4, 6, 3, 2, 7, 8, 1, 9 )
112. ( 5, 4, 6, 3, 2, 7, 8, 9, 1 )
113. ( 5, 4, 6, 3, 7, 2, 1, 8, 9 )
114. ( 5, 4, 6, 3, 7, 2, 8, 1, 9 )
115. ( 5, 4, 6, 3, 7, 2, 8, 9, 1 )
116. ( 5, 4, 6, 3, 7, 8, 2, 1, 9 )
117. ( 5, 4, 6, 3, 7, 8, 2, 9, 1 )
118. ( 5, 4, 6, 3, 7, 8, 9, 2, 1 )
119. ( 5, 4, 6, 7, 3, 2, 1, 8, 9 )
120. ( 5, 4, 6, 7, 3, 2, 8, 1, 9 )
121. ( 5, 4, 6, 7, 3, 2, 8, 9, 1 )
122. ( 5, 4, 6, 7, 3, 8, 2, 1, 9 )
123. ( 5, 4, 6, 7, 3, 8, 2, 9, 1 )
124. ( 5, 4, 6, 7, 3, 8, 9, 2, 1 )
125. ( 5, 4, 6, 7, 8, 3, 2, 1, 9 )
126. ( 5, 4, 6, 7, 8, 3, 2, 9, 1 )
127. ( 5, 4, 6, 7, 8, 3, 9, 2, 1 )
128. ( 5, 4, 6, 7, 8, 9, 3, 2, 1 )
129. ( 5, 6, 4, 3, 2, 1, 7, 8, 9 )
130. ( 5, 6, 4, 3, 2, 7, 1, 8, 9 )
131. ( 5, 6, 4, 3, 2, 7, 8, 1, 9 )
132. ( 5, 6, 4, 3, 2, 7, 8, 9, 1 )
133. ( 5, 6, 4, 3, 7, 2, 1, 8, 9 )
134. ( 5, 6, 4, 3, 7, 2, 8, 1, 9 )
135. ( 5, 6, 4, 3, 7, 2, 8, 9, 1 )
136. ( 5, 6, 4, 3, 7, 8, 2, 1, 9 )
137. ( 5, 6, 4, 3, 7, 8, 2, 9, 1 )
138. ( 5, 6, 4, 3, 7, 8, 9, 2, 1 )
139. ( 5, 6, 4, 7, 3, 2, 1, 8, 9 )
140. ( 5, 6, 4, 7, 3, 2, 8, 1, 9 )
141. ( 5, 6, 4, 7, 3, 2, 8, 9, 1 )
142. ( 5, 6, 4, 7, 3, 8, 2, 1, 9 )
143. ( 5, 6, 4, 7, 3, 8, 2, 9, 1 )
144. ( 5, 6, 4, 7, 3, 8, 9, 2, 1 )
145. ( 5, 6, 4, 7, 8, 3, 2, 1, 9 )
146. ( 5, 6, 4, 7, 8, 3, 2, 9, 1 )
147. ( 5, 6, 4, 7, 8, 3, 9, 2, 1 )
148. ( 5, 6, 4, 7, 8, 9, 3, 2, 1 )
149. ( 5, 6, 7, 4, 3, 2, 1, 8, 9 )
150. ( 5, 6, 7, 4, 3, 2, 8, 1, 9 )
151. ( 5, 6, 7, 4, 3, 2, 8, 9, 1 )
152. ( 5, 6, 7, 4, 3, 8, 2, 1, 9 )
153. ( 5, 6, 7, 4, 3, 8, 2, 9, 1 )
154. ( 5, 6, 7, 4, 3, 8, 9, 2, 1 )
155. ( 5, 6, 7, 4, 8, 3, 2, 1, 9 )
156. ( 5, 6, 7, 4, 8, 3, 2, 9, 1 )
157. ( 5, 6, 7, 4, 8, 3, 9, 2, 1 )
158. ( 5, 6, 7, 4, 8, 9, 3, 2, 1 )
159. ( 5, 6, 7, 8, 4, 3, 2, 1, 9 )
160. ( 5, 6, 7, 8, 4, 3, 2, 9, 1 )
161. ( 5, 6, 7, 8, 4, 3, 9, 2, 1 )
162. ( 5, 6, 7, 8, 4, 9, 3, 2, 1 )
163. ( 5, 6, 7, 8, 9, 4, 3, 2, 1 ) (70 lists start with 5)

 

164. ( 6, 5, 4, 3, 2, 1, 7, 8, 9 )
165. ( 6, 5, 4, 3, 2, 7, 1, 8, 9 )
166. ( 6, 5, 4, 3, 2, 7, 8, 1, 9 )
167. ( 6, 5, 4, 3, 2, 7, 8, 9, 1 )
168. ( 6, 5, 4, 3, 7, 2, 1, 8, 9 )
169. ( 6, 5, 4, 3, 7, 2, 8, 1, 9 )
170. ( 6, 5, 4, 3, 7, 2, 8, 9, 1 )
171. ( 6, 5, 4, 3, 7, 8, 2, 1, 9 )
172. ( 6, 5, 4, 3, 7, 8, 2, 9, 1 )
173. ( 6, 5, 4, 3, 7, 8, 9, 2, 1 )
174. ( 6, 5, 4, 7, 3, 2, 1, 8, 9 )
175. ( 6, 5, 4, 7, 3, 2, 8, 1, 9 )
176. ( 6, 5, 4, 7, 3, 2, 8, 9, 1 )
177. ( 6, 5, 4, 7, 3, 8, 2, 1, 9 )
178. ( 6, 5, 4, 7, 3, 8, 2, 9, 1 )
179. ( 6, 5, 4, 7, 3, 8, 9, 2, 1 )
180. ( 6, 5, 4, 7, 8, 3, 2, 1, 9 )
181. ( 6, 5, 4, 7, 8, 3, 2, 9, 1 )
182. ( 6, 5, 4, 7, 8, 3, 9, 2, 1 )
183. ( 6, 5, 4, 7, 8, 9, 3, 2, 1 )
184. ( 6, 5, 7, 4, 3, 2, 1, 8, 9 )
185. ( 6, 5, 7, 4, 3, 2, 8, 1, 9 )
186. ( 6, 5, 7, 4, 3, 2, 8, 9, 1 )
187. ( 6, 5, 7, 4, 3, 8, 2, 1, 9 )
188. ( 6, 5, 7, 4, 3, 8, 2, 9, 1 )
189. ( 6, 5, 7, 4, 3, 8, 9, 2, 1 )
190. ( 6, 5, 7, 4, 8, 3, 2, 1, 9 )
191. ( 6, 5, 7, 4, 8, 3, 2, 9, 1 )
192. ( 6, 5, 7, 4, 8, 3, 9, 2, 1 )
193. ( 6, 5, 7, 4, 8, 9, 3, 2, 1 )
194. ( 6, 5, 7, 8, 4, 3, 2, 1, 9 )
195. ( 6, 5, 7, 8, 4, 3, 2, 9, 1 )
196. ( 6, 5, 7, 8, 4, 3, 9, 2, 1 )
197. ( 6, 5, 7, 8, 4, 9, 3, 2, 1 )
198. ( 6, 5, 7, 8, 9, 4, 3, 2, 1 )
199. ( 6, 7, 5, 4, 3, 2, 1, 8, 9 )
200. ( 6, 7, 5, 4, 3, 2, 8, 1, 9 )
201. ( 6, 7, 5, 4, 3, 2, 8, 9, 1 )
202. ( 6, 7, 5, 4, 3, 8, 2, 1, 9 )
203. ( 6, 7, 5, 4, 3, 8, 2, 9, 1 )
204. ( 6, 7, 5, 4, 3, 8, 9, 2, 1 )
205. ( 6, 7, 5, 4, 8, 3, 2, 1, 9 )
206. ( 6, 7, 5, 4, 8, 3, 2, 9, 1 )
207. ( 6, 7, 5, 4, 8, 3, 9, 2, 1 )
208. ( 6, 7, 5, 4, 8, 9, 3, 2, 1 )
209. ( 6, 7, 5, 8, 4, 3, 2, 1, 9 )
210. ( 6, 7, 5, 8, 4, 3, 2, 9, 1 )
211. ( 6, 7, 5, 8, 4, 3, 9, 2, 1 )
212. ( 6, 7, 5, 8, 4, 9, 3, 2, 1 )
213. ( 6, 7, 5, 8, 9, 4, 3, 2, 1 )
214. ( 6, 7, 8, 5, 4, 3, 2, 1, 9 )
215. ( 6, 7, 8, 5, 4, 3, 2, 9, 1 )
216. ( 6, 7, 8, 5, 4, 3, 9, 2, 1 )
217. ( 6, 7, 8, 5, 4, 9, 3, 2, 1 )
218. ( 6, 7, 8, 5, 9, 4, 3, 2, 1 )
219. ( 6, 7, 8, 9, 5, 4, 3, 2, 1 ) (56 lists start with 6)

 

220. ( 7, 6, 5, 4, 3, 2, 1, 8, 9 )
221. ( 7, 6, 5, 4, 3, 2, 8, 1, 9 )
222. ( 7, 6, 5, 4, 3, 2, 8, 9, 1 )
223. ( 7, 6, 5, 4, 3, 8, 2, 1, 9 )
224. ( 7, 6, 5, 4, 3, 8, 2, 9, 1 )
225. ( 7, 6, 5, 4, 3, 8, 9, 2, 1 )
226. ( 7, 6, 5, 4, 8, 3, 2, 1, 9 )
227. ( 7, 6, 5, 4, 8, 3, 2, 9, 1 )
228. ( 7, 6, 5, 4, 8, 3, 9, 2, 1 )
229. ( 7, 6, 5, 4, 8, 9, 3, 2, 1 )
230. ( 7, 6, 5, 8, 4, 3, 2, 1, 9 )
231. ( 7, 6, 5, 8, 4, 3, 2, 9, 1 )
232. ( 7, 6, 5, 8, 4, 3, 9, 2, 1 )
233. ( 7, 6, 5, 8, 4, 9, 3, 2, 1 )
234. ( 7, 6, 5, 8, 9, 4, 3, 2, 1 )
235. ( 7, 6, 8, 5, 4, 3, 2, 1, 9 )
236. ( 7, 6, 8, 5, 4, 3, 2, 9, 1 )
237. ( 7, 6, 8, 5, 4, 3, 9, 2, 1 )
238. ( 7, 6, 8, 5, 4, 9, 3, 2, 1 )
239. ( 7, 6, 8, 5, 9, 4, 3, 2, 1 )
240. ( 7, 6, 8, 9, 5, 4, 3, 2, 1 )
241. ( 7, 8, 6, 5, 4, 3, 2, 1, 9 )
242. ( 7, 8, 6, 5, 4, 3, 2, 9, 1 )
243. ( 7, 8, 6, 5, 4, 3, 9, 2, 1 )
244. ( 7, 8, 6, 5, 4, 9, 3, 2, 1 )
245. ( 7, 8, 6, 5, 9, 4, 3, 2, 1 )
246. ( 7, 8, 6, 9, 5, 4, 3, 2, 1 )
247. ( 7, 8, 9, 6, 5, 4, 3, 2, 1 ) (28 lists start with 7)

 

248. ( 8, 7, 6, 5, 4, 3, 2, 1, 9 )
249. ( 8, 7, 6, 5, 4, 3, 2, 9, 1 )
250. ( 8, 7, 6, 5, 4, 3, 9, 2, 1 )
251. ( 8, 7, 6, 5, 4, 9, 3, 2, 1 )
252. ( 8, 7, 6, 5, 9, 4, 3, 2, 1 )
253. ( 8, 7, 6, 9, 5, 4, 3, 2, 1 )
254. ( 8, 7, 9, 6, 5, 4, 3, 2, 1 )
255. ( 8, 9, 7, 6, 5, 4, 3, 2, 1 ) (8 lists start with 8)

 

256. ( 9, 8, 7, 6, 5, 4, 3, 2, 1 ) (1 list start with 9)

 

laugh

07.03.2016
 #2
avatar+26396 
+5

the point (1,3) is rotated 90 degrees about the origin and then reflected across the y- axis. What are the coordinators of the image?

 

Rotation counter clockwise 90:(cos(90)sin(90)sin(90)cos(90))=(0110)Refection y-axis:=(1001)Rotation counter clockwise 90×Reflection y-axis:(0110)(1001)=(0110)Point(xp,yp)× Rotation counter clockwise 90×Reflection y-axis:(xp,yp)(0110)=(yp,xp)Point(1,3)× Rotation counter clockwise 90×Reflection y-axis:(1,3)(0110)=(3,1)

 

change x and y Reflection at line y = x

 

laugh

07.03.2016