4) 60/90 = 2/3
15/50 = 3/10
ноз. 20/30 и 9/30
5) 10/20 = 1/2
8/24 = 1/3
9/45 = 1/5
ноз. 15/30 и 10/30 и 6/30
6) 22/44 = 11/22
24/30 = 4/5
27/36 = 3/4
ноз. 165/220 и 110/220 и 176/220
