Answer:
The answer is 1
Explanation:
8/20 or 0.4- probability of red ball in one draw
2/20 or 0.1 - probability of white ball in one draw
10/20 or 0.5 - probability of black ball in one draw
0.4 + 0.5 + 0.1 = 1
Sorry I'm late just wanted to put the right answer!