2/3 > 8/21,т.к. 2/3=14/21
4/15<2/5, 2/5=6/15
7/30 <3/10, 3/10=9/30
19/60> 4/16 19/60= 76/240, 4/16=60/240
2/3 > 8/21,т.к. 2/3=14/21
4/15<2/5, 2/5=6/15
7/30 <3/10, 3/10=9/30
19/60> 4/16 19/60= 76/240, 4/16=60/240