Сравните дроби: 3/8 и 1/6; 5/8 и 7/10; 3/7 и 9/21; 3/5 и 5/8; 7/12 и 11/18; 10/21 и 9/14;

Для сравнения дробей надо привести их к общему знаменателю.
3/8 и 1/6 --- общий знаменатель 24
9/24 и 4/24 9/24 > 4/24
3/8 > 1/6

5/8 и  7/10  общ. знам. = 40
25/40 и 28/40 25/40 < 28/40
5/8 < 7/10

3/7 и 9/21 общ.знам. = 21
9/21 = 9/21
3/7 = 9/21

3/5 и 5/8 общ.знам. = 40
24/40  и 25/40 24/40 < 25/40
3/5 < 5/8

7/12 и 11/18 общ.знам. = 36
21/36 и 22/3621/36< 22/36
7/12 < 11/18

10/21  и 9/14 общ.знам. = 42
20/42 и 27/42 20/42 < 27/42
10/21 < 9/14