If Bob picks the balls with replacement the chance of getting a white ball is 3 (the number of white balls) out of 8 (the total number of balls), i.e. 3/8 or 37.5%. If it is 'and and' (both the first AND the second ball should be white) you need to use the multiplication rule. So 3/8 * 3/8 = 9/64.

If you do not use replacement the first is still 3/8 like above. But the second ball is 2/7 since there is only 2 white balls left and only 7 left in total. Again you need to multiply. So now its 6 / 56 which can be reduced to 3 / 28.
spam fails_task lang_mismatch pii not_appropriate hate_speech sexual_content quality toxicity humor helpfulness creativity violence