At this question, why I have used 52 for both trials, doesn't it be 51 for the second trial as I keep the ball out of the bowl, so the number of balls I drag from decrease by one.

Hey Omar, Thank you for reaching out! I am not sure I understand your question in the context of this exercise. You are referring to the problem where there are 42 black balls and 12 white ones inside a bowl, correct? Kind regards, 365 Hristina

Hey again Omar, You need to consider 1. the number of ways in which you can choose 1 black ball from 42, 2. the number of ways in which you can choose 1 white ball from 12, 3. and the number of ways in which you can choose 2 balls from a total of 54. Please, refer to the explanation of the correct answer for a more in-depth solution. Kind regards, 365 Hristina