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数学 高校生

なんで(2)は÷3して(3)は割らないのですが。 教えてください。

2順 例題 165 円順列(1) *** a,b,c,d, e の文字が書かれた玉が1個ずつあるとき,次の問いに答 えよ. (1)これらの玉を円形に並べる方法は何通りあるか. F(2) これらの5個から3個を取り出して円形に並べる方法は何通りある か. (3)abが隣り合うように円形に並べる方法は何通りあるか. (4) これらの玉にひもを通し, 輪を作る方法は何通りあるか. 考え方 (2) 異なる3個の円順列と同様に5個から3 個選んだ場合も, 重複する場合がある. a C (3) a, bを1つの玉とし, 4個の円順列を考 える。 (4) ひもを通して輪を作るとき, 右のように円 順列では異なる2通りが、ひっくり返すと 同じものになっている. よって, 円順列の 場合の数を2で割ることで求められる. 解答 (1) 異なる5個の円順列であるから, a 338 (5-1)!=4!=4・3・2・1=24 (通り)ピードメー (2)異なる5個から3個選んだ円順列であるから, 5P3 5.4.3 = =20(通り) 3 3 (3)a,bを1つの玉と考えると, 4個の円順列より, (4-1)!=3!=3・2・1=6(通り) a, b の並べ方はaとbaの2通り よって, 6×2=12(通り) (4)5個の円順列において,ひっくり返すと同じものが (5-1)!_4・3・2・1 3つずつの重複がある. Cab 積の法則 ba 異なるn個のじゅず 2. との 3 順列 よって=12(通り)の来 (n-1)!通り 2 Focus どのように重複をとりのぞくかに着目する と書かれた玉が1個ずつあるとき、 次の問いに答え 339

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英語 高校生

この英文から、なぜ筆者のプランは毎月100ドル以上かかったと言えないのか教えてほしいです

B You are a college student going to study in the US and need travel insurance. You find this review of an insurance plan written by a female international student who studied in the US for six months. 0 There are many things to consider before traveling abroad: pack appropriate clothes, prepare your travel expenses, and don't forget medication (if necessary). Also, you should purchase travel insurance. Imam gavo 0012 1ovo od 1200 sla When I studied at Fairville University in California, I bought travel insurance from TravSafer International. I signed up online in less than 15 minutes and was immediately covered. They accept any form of payment, usually on a monthly basis. There were three plans. All plans include a one-time health check-up. gisinal The Premium Plan is $100/month. The plan provides 24-hour medical support through a smartphone app and telephone service. Immediate financial support will be authorized if you need to stay in a hospital. It had the 24-hour telephone The Standard Plan worked best for me. assistance and included a weekly email with tips for staying healthy in a foreign country. It wasn't cheap: $75/month. However, it was nice to get the optional 15% discount because I paid for six months of coverage in advance. If your budget is limited, you can choose the Economy Plan, which is $25/month. It has the 24-hour telephone support like the other plans but only covers emergency care. Also, they can arrange a taxi to a hospital at a reduced cost if considered necessary by the support center. I never got sick or hurt, so I thought it was a waste of money to get insurance. Then my friend from Brazil broke his leg while playing soccer and had to spend a few days in a hospital. He had chosen the Premium Plan and it covered everything! I realized how important insurance is-you know that you will be supported when you are in trouble.

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