1) (21+5+18+19+15+12) : 6 = 15 (15 - С.А.)
2) 18, 17, 17, 15, 11, 17, 18, 16, 18, 16, 17 (М. - 17)
3) 29, 16, 25, 12, 19, 11, 14 29-11=18 (Р. - 18
4) (15+15+15+15+15+15+15) : 7= 15 (15 - С.А.)
(15 - М.)
15-15=0 (0 - Р.)