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Mathematical possibilities need to be explained! thank you
The possibility of touching a red ball is 1/5, and the possibility of touching a red ball and a white ball is 3/5.

If you don't understand, you can ask.

Red 1, red 2; Red 1, red 3; Red 2, red 3; White 1, white 2; White 1, white 3; White 2, white 3;

Red 1, white 1, red 1, white 2; Red 1, white 3; Red 2, white1; Red 2, white 2; Red 2, white 3; Red 3, white1; Red 3, white 2; Red 3, white 3; *** 15, the possibility of touching the red ball is 3/ 15, and the possibility of touching one red and one white is 9/ 15. I hope I can help you.