1+1
2
10-5
5
10,20,30,40
by 10
7+3
10
20-15
100,70,40,10
by 30
16+8
24
38-20
8
65,50,35,10
by 15
35+15
50
65-35
30
100,80,60,40,20
by 20
65+33
98
100-85
15
100,75,50,25
by 25