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数学 高校生

(4)がわかりません。2回とも違うやり方で解いてみたのですが、答え(画像3枚目)と一致しません。それぞれどこからどう間違えているのかを教えてください。

3 はじめに Aが赤玉を1個. Bが白玉を1個 Cが青玉を1個持っている。 表裏の出る確率がそれぞれの硬貨を投げ 表が出ればAとBの玉を交換し、裏が出ればBとCの玉を交換する。 という操作を考える。この操作を回 (= 1, 2, 3. くり返した後にA, B, C 赤玉を持っている確率をそれぞれ とおく。 (1) ar by y z by c」 を求めよ。 12abca da catt. (3)が奇数ならば, b. >が成り立ちが偶数ならばa, b, cx が成り立つことを示せ。 (4) 6. を求めよ。 3 (解答欄 1枚目) A (赤) B (青) (1)ai操作を1回した後にAが赤玉を もっている確率 001 (2) 赤玉をもっている人を考える。 n@e A nt1回目 au ABC B bul Chel Cutl=2/26m+/2/cm③ an これが起こるのは、BとCが玉を交換 するときであるから、 a₁ = 2 =1/2 bu B Cu C 操作を1回行った後にBが赤玉をもって いるためには、AとBが交換すれば よいから、 ± anti=1/2an+/bm ① but = 1/ant/cu ② 操作を1回行った後にCが赤玉を もっていることは起こり得ないから、 C₁ =0 (3)(ⅰ) n=1のとき ここで、AとBが玉を交換する事象をX BとCが玉を交換する事象をYとすると、 操作を2回行った後にAが赤玉を もっているためには XXまたは→Yが起こればよいので 02=(1/+112=1/2 H 操作を2回行った後にBが赤玉を もっているためには、 Y→Xが起こればよいから、 b2=1/1/1/2=1/ H 操作を2回行った後にCが赤玉を もっているためには、 XYが起こればよいから、 C2=1/2/1/2=1/ a₁ = b₁ = ½ C₁ = 0 より、n=1(奇数)のとき a,b,c,が成り立つ。 (ii) n=2のとき a2=1/21b2=C2=1/ より、n=2(偶数)のとき、 az> b2=C2が成り立つ。 (iii) n=2kgとき azk>bzk=Czk4 が成り立つとすると、 n=2kt1のとき、①~③より A24+1 == Ask + ½ bak...' bakt1= 1/art/2C2・・・②' 単元ジャンル演習 解答用紙 1/2ページ C24t=1/2b2k+1/Czk・・・③' 名古屋大学全学部 2010年度 数学1 第3問 旧帝大文系数学対策演習場 東進ハイスクール 東進衛星予備校 2/2 3(解答欄2枚目) ①②より ab2=1/2624-12/2 = 0 (4) よって、azkt1=b2k+1 ②に代入して、 THE bm1-1/2 (Cat() +12cm =Cut(m/ bute = G - Cu = bui- (2) Cuts = bute" ③に代入して、 Pentel Ain 軽く消 - Aker-Cake - Cak bur-(+) but ½ (ber (1)~) = = 1 (024 - (24) 70\ よって、ask>C2kti in=2k+1のとき (4) a2kt1=b2kt>C2k+1は成立する。 (iv) n=2ℓ-1のとき a22-1=b2e-1>C20-1⑤が 成り立つと仮定すると、 h=2ℓのとき ①~③より >= 2+ + 2 " bal = = a++ / Call ---" C2=1/2bay+/Coat ③〃 ①'@'aze-box=2/12(624-1-Czen) 20 よって、azbze -③"box-Cz=2/12 (ab1-628-) =0 (:⑤) よって、 b2x=C2 n=2ℓのとき aze>bal=Czは成立する。 (-) (ⅰ)~(iv)より、すべての自然数nにおいて、 nが奇数のときan=buCuが成り立ち、 へが偶数のときan>bm=cuが成り立つ (4) ①-③ より (証明終) anti-Cut=1/2(am-cu) 数列{an-c}は初項ar-c1/2、公比1/2の等比 数列だから、an-Ch=(1/2)man=Cut (63) bmtz-1/26mt1-1/26m=0 bmz+/bm=bmit/bu =bn-1/2bm b₂-b₁ = 0 よって、bait/bm=0 bnti=-1/2bu 数列{bo}は初項bi-/、公比-1/2 の等比数列であるから、 bm=1/2(-1/2)-1 + 単元ジャンル演習 解答用紙 2/2ページ 得点

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英語 中学生

四角Bが、 アになる訳が分かりません、 ウだと思いました💦

2次会話は、高校生の茜、 壮太と、オーストラリアからの留学生のジャックが、 ある 話題について休み時間に話したときのものです。また、グラフ1は、そのとき茜たちが 見ていたウェブページの一部です。これらに関して、あとの1~5に答えなさい。 Akane : Hi, Jack! Can we ask you something? We have Jack Sota Jack about eco-tours since this morning. A a presentation : Sure. Eco-tours are an interesting topic! They're becoming popular in many countries. : Yes! On eco-tours, tourists can enjoy nature and also learn about it, right? : That's right. On eco-tours, people don't just visit places. They learn about nature, animals, the local history, and traditional cultures. And they often talk with local people to understand more. Akane: It's different from normal trips. Jack : Yes, it is. The theme of eco-tours is protecting nature. People can enjoy the trip more deeply by learning about nature and helping to protect it. Sota : I hear that eco-tours started in Australia Jack : Yes. The Australian government started promoting eco-tours in the 1990s. People began going to forests, mountains, or Aboriginal villages. Akane: Have you ever joined an eco-tour? Jack Sota : Yes, I have! I once visited an Aboriginal village. I talked with Aborigines, saw how they lived and walked in the forest with a local guide. I really enjoyed it and took many pictures. I'll show you some next time! : Sounds exciting! I also want to experience an eco-tour in Australia someday. Jack : You should! B do you know any good places for eco-tours in Japan? Akane: Yes! Okinawa is a great place for eco-tours. I found a graph on the internet. It shows that the number of people who joined eco-tours in Okinawa increased from 2013 to 2017. In 2017, more than 500,000 people joined. Jack : 500,000 people? That's great! Akane Yes. The graph also shows that C Sota Jack Sota foreign tourists joined eco-tours than Japanese tourists in 2015 and 2017. The number of Japanese tourists in 2017 was only about 100,000. : I hope a lot of Japanese people will try eco-tours. Actually, I went to Iriomote Island in Okinawa last summer with my family. : Oh, nice! What did you do there? : We joined an eco-tour there. We went canoeing on the river and hiking in the jungle A local guide showed us many wild animals and plants. He also told us stories about life on the island.

解決済み 回答数: 1
英語 中学生

【急募】 高専の過去問なんですが和訳ができないんで教えてください。また、英語の問題の解説もお願いします。

5 次の英文は,家族の夜の外食行動(eating out behavior)に関する調査について述べたもので ある。英文と表を良く読み, あとの問題に答えなさい。 なお, 計算等を行う場合は、この問題の ページの余白で行うこと。 Kakeru and his friend Judy go to a university in Japan. They decided to work together to do some research about people's eating out behavior at night. They sent several questions to 300 families with children in elementary or junior high school. They asked what day of the week the families eat out at night the most and what their primary reason for eating out is. The results are shown in the tables below. Table 1 shows the days of eating out at night. According to the results of the survey, Monday is the lowest percent of all. Only one percent of the families eat out on Monday. The percent of families who eat out on Thursday is half of the percent of Wednesday. On Sunday, ten percent of families eat out. The rate of families choosing Friday or Saturday night for eating out is more than 70 percent, and Friday is higher than Saturday. Why do more families choose Friday and not Saturday for eating out? Many adults and children are on a five-day week, and Saturdays and Sundays are their days off. So, they eat out on Friday night as a reward for finishing the week's work or school. In Table 2, we can see various reasons for eating out at night, but more than 60 percent of the answers are related only to parents. Parents usually make meals for the family, and other members sometimes help to cook. As a result, when parents cannot make dinner, the family eats out. The percent of "For a change" is about half of "All family members come home too late." The research also shows that most children want to eat out more often, but about 50 percent. of parents think they eat out too much. They worry about the cost of eating at restaurants. Table 1 Days of eating out Day Percent (%) Table 2 Reasons to eat out Reason Percent (%) Monday Tuesday Wednesday 8 Thursday Friday ( A ) ( B Saturday ( C ) Sunday Total amount 10 100 1 Parents come home too late 36 2 P 27 Q 15 R ) 11 Others For a change Total amount 7 4 100 (注) primary 第一位の on a five-day week 週5日勤務の be related to ~~と関係がある cost table day off for a change 気分転換に total amount it rate A reward ごほうび late 遅くに -5-

解決済み 回答数: 1