Question

求50道带分数题

整数不得超过三，分母不得超过20，分子不得超过10.
是乘法题

Answer 1

1/20, 1/19, 1/18, 1/17, 1/16, 1/15, 1/14, 1/13, 1/12, 1/11, 1/10, \
2/19, 1/9, 2/17, 1/8, 2/15, 1/7, 3/20, 2/13, 3/19, 1/6, 3/17, 2/11, \
3/16, 1/5, 4/19, 3/14, 2/9, 3/13, 4/17, 1/4, 5/19, 4/15, 3/11, 5/18, \
2/7, 5/17, 3/10, 4/13, 5/16, 6/19, 1/3, 7/20, 6/17, 5/14, 4/11, 7/19, \
3/8, 5/13, 7/18, 2/5, 7/17, 5/12, 8/19, 3/7, 7/16, 4/9, 9/20, 5/11, \
6/13, 7/15, 8/17, 9/19, 1/2, 10/19, 9/17, 8/15, 7/13, 6/11, 5/9, \
9/16, 4/7, 7/12, 10/17, 3/5, 8/13, 5/8, 7/11, 9/14, 2/3, 9/13, 7/10, \
5/7, 8/11, 3/4, 10/13, 7/9, 4/5, 9/11, 5/6, 6/7, 7/8, 8/9, 9/10, \
10/11, 1, 10/9, 9/8, 8/7, 7/6, 6/5, 5/4, 9/7, 4/3, 7/5, 10/7, 3/2, \
8/5, 5/3, 7/4, 9/5, 2, 9/4, 7/3, 5/2, 8/3, 3

方法：Union[Flatten[Table[#/j, {j, 1, 20}] & /@ Range[10]]] // Sort
然后取小于等于3的就是了，共117个。