Zadanie 20 :
25 : 6 = 4 r 1 bo 6 * 4 + 1 = 25
20 : 9 = 2 r 2 bo 9 * 2 + 2 = 20
30 : 7 = 4 r 2 bo 7 * 4 + 2 = 30
42 : 5 = 8 r 2 bo 5 * 8 + 2 = 42
38 : 4 = 9 r 2 bo 4 * 9 + 2 = 36
Zadanie 21 :
160 = 2 * 80
160 = 4 * 40
360 = 3 * 120
360 = 6 * 60
300 = 2 * 150
300 = 3 * 100