かきつばた almost 3 yearsago ⑴は6個の頂点の中から4個選ぶから 6C4=6C2=15 ⑵は6個の頂点の中から2個選ぶけど、隣の頂点は選ばない。 6c2-6=9 Post A Comment
![基本例題の[2]についてです。ここの条件ですが、
a/3<=1<=4a/3とありますが4a... - 1](https://d1e9oo257tadp1.cloudfront.net/uploads/qa_question_image/file/1810404/thumb_l_webp_70236300-B387-4A8D-A246-76C58E626EEE.webp?Expires=1787737168&Signature=RQ~pjjUP~RIv-mzggpW~SlxtJOtj0meh6wCc3bCDRMAFB2OS-j~z6VMFgHZ3~lgh0aEneNqszI~5ZaO3pITxfkXPBHx1ksydIxmxj5K67z1ZEqiShOW8lWSpldx5WCCSxblqQcptbgIVfuHiv9Jwb1FjAfX7lxsUpUOHekgnPsDmPMdfYoajbF-zLjXFn3MzbEvkiaUguXGGRgMGfwtfXPpEBm-QpUqoMXjHDrHou-TirgGXjCoagVyhG1jdagY3ex4Mj0AZhsB7QjniKoYsuTdIFg5jtxNi2dKcRN8T8p26xuRnowg5JO4bvlxSRpY0-vKtcwuoxSGZnEgVhUUgxw__&Key-Pair-Id=K2W722D70GJS8W&Expires=1787737168&Signature=YpAP303sPENz8sEy8MFpAmsvlGEJVFs3i1Aj~rJOAiErrD5YszR-3CidLKQdQwpA0avwGp3eHiNdCOtsrExq64pAOmECZfgli1Nq9doYjVajXWCQfCt-U2ql2ff7bXuUoTtScDYeapHOxGRtoI-pUS5QTug7OWakJ65lD7trMpZywvpRkRtfJboZBpOnxDwVuvVqOK341Q~rTYUlDx6yWGLsZkJzCkq7u4oCqqhU2TSa~0qJ1cvNeb6BRmT7-SQXPYo0cCh7dwWaBA3fmWp0bDQa2~OetSq3YjLZ2RSRCv0dHLYCaAo9z~PscC5v7bCFc66v0jItGpOAbWSg85fv7A__&Key-Pair-Id=K2W722D70GJS8W)
