2/3,1/2,3/7,7/18,() a5/9 b4/11 c3/13 d2/5

问题描述:

2/3,1/2,3/7,7/18,() a5/9 b4/11 c3/13 d2/5

2/3,1/2,3/7,7/18,(4/11)
2/3=4/6
1/2=5/10
3/7=6/14
7/18=7/18
分子成公差为1的等差数列,分母为公差为4的等差数列
所以下一个为
8/22=4/11