中学生网络课堂本课配套习题挑战模式1/5
单选题
难度系数：
1.如图，从A→C，有 种不同走法.
| A: 4 |
| B: 5 |
| C: 6 |
| D: 7 |
一次做对，真牛！
+5奖励规则>
- 提示1：IOacieS4pOenjeaWueazle+8jDHvvIznm7TmjqXku45B6LWw5YiwQywy77yM5LuOQeWIsELlho3liLBDLg==
- 提示2：IOesrOS4gOenjeaWueazleaciTLpgInmi6njgILnrKzkuoznp43mlrnms5XmnIk8aW1nIHdpZHRoPTU4IGhlaWdodD0yMSBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwLzBFL0FEL3JCQUNGRk4walhXaTF6RExBQUFCc0c1UHg3bzIyOS5wbmciPuenjeaWueazle+8gQ==
- 提示3：IOagueaNruWIhuexu+WKoOazleiuoeaVsOWOn+eQhuWFseaciTxpbWcgd2lkdGg9NTggaGVpZ2h0PTIxIHNyYz0iaHR0cHM6Ly9wMS5xaW5nZ3VvLmNvbS9HMS9NMDAvNEEvQjQvckJBQ0UxTjBqWFhBZGxPd0FBQUJxZmlpdzNRNzE2LnBuZyI+56eN5pa55rOV77yB
- 答案：Qw==
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
本课配套习题挑战模式2/5
单选题
难度系数：
2.
将三封信投入4个邮箱，不同的投法有 种.
| A:
|
| B:
|
| C: 12 |
| D: 9 |
一次做对，真牛！
+5奖励规则>
- 提示1：PHA+5L+h5piv5Li75L2T77yM6K6p5L+h5Y676YCJ5oup6YKu566x77yM56ys5LiA5bCB5L+h5pyJNOenjemAieaLqe+8jOesrOS6jOWwgeS/oeaciTTnp43pgInmi6nvvIznrKzkuInlsIHkv6HmnIk056eN6YCJ5oup44CCPGJyPjwvcD4=
- 提示2：PHA+5YWx5pyJPGltZyBzcmM9Imh0dHBzOi8vcDIucWluZ2d1by5jb20vRzEvTTAwLzBFL0FEL3JCQUNGRk4walkzRDB2U1FBQUFCdnhsRWxRNDU0OC5wbmciIGRhdGEtY2tlLXNhdmVkLXNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvMEUvQUQvckJBQ0ZGTjBqWTNEMHZTUUFBQUJ2eGxFbFE0NTQ4LnBuZyIgaGVpZ2h0PSIyMSIgd2lkdGg9Ijg4Ij7np43mlrnms5U8L3A+
- 答案：Qg==
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
本课配套习题挑战模式3/5
单选题
难度系数：
3.一个口袋内装有5个小球，另一个口袋内装有4个小球，所有这些小球的颜色互不相同，从两个口袋内各取一个小球，有__________种不同的取法.
| A: 5 |
| B: 4 |
| C: 9 |
| D: 20 |
一次做对，真牛！
+5奖励规则>
- 提示1：IOWIhuatpemqpOWOu+WBmu+8jOesrOS4gOatpe+8mumAieaLqeaciTXkuKrnkIPnmoTlj6PooovvvIzmnIk156eN6YCJ5oup5pa55byP44CC56ys5LqM5q2l77ya6YCJ5oup5pyJNOS4queQg+eahOWPo+iii++8jOaciTTnp43pgInmi6nmlrnlvI/jgII=
- 提示2：IOagueaNruWIhuatpeS5mOazleiuoeaVsOWOn+eQhu+8jOWFseaciTxpbWcgd2lkdGg9NjUgaGVpZ2h0PTIxIHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvMEUvQUUvckJBQ0ZGTjBqZFBoWkVEUEFBQUIzbm9OMDBjMDg3LnBuZyI+56eN5pa55rOV44CC
- 答案：RA==
6Kej77ya5YiG5q2l6aqk5Y675YGa77yM56ys5LiA5q2l77ya6YCJ5oup5pyJNeS4queQg+eahOWPo+iii++8jOaciTXnp43pgInmi6nmlrnlvI/jgILnrKzkuozmraXvvJrpgInmi6nmnIk05Liq55CD55qE5Y+j6KKL77yM5pyJNOenjemAieaLqeaWueW8j+OAguagueaNruWIhuatpeS5mOazleiuoeaVsOWOn+eQhu+8jOWFseaciTxpbWcgd2lkdGg9NjUgaGVpZ2h0PTIxIHNyYz0iaHR0cHM6Ly9wMi5xaW5nZ3VvLmNvbS9HMS9NMDAvMEUvQUUvckJBQ0ZGTjBqZFBoWkVEUEFBQUIzbm9OMDBjMDg3LnBuZyI+56eN5pa55rOV44CC
本课配套习题挑战模式4/5
单选题
难度系数：
4.用0，1，2，3，4，5六个数字组成无重复数字的四位数，比3410大的四位数有_______个
| A: 140 |
| B: 120 |
| C: 110 |
| D: 80 |
一次做对，真牛！
+5奖励规则>
- 提示1：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
- 答案：QQ==
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
本课配套习题挑战模式5/5
单选题
难度系数：
5.某出版社的7名工人中，有3人只会排版，2人只会印刷，还有2人既会排版又会印刷，现从7人中安排2人排版，2人印刷，有_________种不同的安排方法.
| A: 37 |
| B: 6 |
| C: 36 |
| D: 24 |
一次做对，真牛！
+5奖励规则>
- 提示1：IOWPr+WwhumXrumimOWIhuaIkDPnsbvvvIznrKwx57G777ya5LuO5Y+q5Lya5o6S54mI55qEM+S6uuS4remAiTLkurrvvIzmnIkz56eN6YCJ5rOV77yb5Y+q5Lya5Y2w5Yi355qEMuS6uuWFqOiiq+mAieWHuu+8jOaciTHnp43pgInms5XvvIznlLHliIbmraXorqHmlbDljp/nkIbnn6XlhbHmnIkzw5cxPTPnp43pgInms5Uu
- 提示2：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
- 提示3：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
- 答案：QQ==
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
