a maths question, page-37

here is the scenario
left column is draw
second coloumn is favourable outcome (white marble drawn)
third column is unfavourable outcome (black drwan)
foruth and fifth are the odds
favourable unfavourable
draw white black odds
1 25 5 5 1
2 24 5 5 1
3 23 5 5 1
4 22 5 4 1
5 22 4 6 1
6 22 3 7 1
7 21 3 7 1
8 21 2 11 1
9 20 2 10 1
10 19 2 10 1
11 18 2 9 1
12 17 2 9 1
13 16 2 8 1
14 15 2 8 1
15 14 2 7 1
16 13 2 7 1
17 12 2 6 1
18 11 2 6 1
19 10 2 5 1
20 9 2 5 1
21 8 2 4 1
22 7 2 4 1
23 6 2 3 1
24 5 2 3 1
25 5 1 5
26 5 0
27 4 0
28 3 0
29 2 0
30 1 0